I wonder if the scent of the soap has some sort of relaxing effect.
Started poking around to read about quinine in general, and came across a recommendation from the FDA that quinine is not to be used off-label for the treatment of RLS.
My sheets are washed in Tide. doesn’t that count?
(Maybe that is why the first night in clean sheets, it feels so much better!)
I suspect that the soap being down there somehow encourages you to sleep with your knees bent, or on your side.
If you sleep on your back, with your toes being pushed on by the top sheet, that can cause the Achilles tendon to contract, and in turn cramps up the calf muscle, which eventually rebels.
OTOH, if you sleep with your toes up (feet flat as if you were walking) that lengthens the Achilles and the calf muscle, so it’s far less likely to happen. I can see how the soap being down there might make you hold your feet differently.
Same general principle as these: http://bracesupport.com/90%20Degree%20Night%20Splint.htm
Fortunately, my wife is taking quinine under a prescription for genuine leg cramps and not RLS so I don’t have to worry on that count, but that is good to know.
I find that a teaspoon of yellow mustard before bedtime eliminates my leg cramps entirely. Placebo? I dunno…
Do you apply it topically to the affected area? 
I get RLS but only on car trips, not in bed. It’s a pain in the hoohah.
No, just take it internally. This is an old folk remedy that I’ve recommended to others and it’s worked very well with them. Try it. What can you lose?
Please let me know… (Make sure it’s yellow mustard though)
Did you read the link? Qualaquin is *only *approved as an anti-malarial, *not *for either leg cramps or RLS.
I thought the latter was from a different problem entirely.
I didn’t read the link, just the poster’s statement that it wasn’t approved for RLS. My wife’s problem is nothing at all related to RLS or night-time leg cramps - has more to do with a surgery involving the achilles tendon and the cramps tend to strike at any time of the day. I also notice that the date of the announcement is after the last time she was prescribed this, so I’ll bring it up to her as something to talk with her doctor about next time.
I find if I am careful to keep my self hydrated, I have fewer leg cramps. I I wake up with a full bladder, I can quickly and easily fix that. Leg cramps?
geezer1 here – new kid on the block . . .hello everyone . . .
At a Church Council meeting, I had to stand in the back of the room, due to leg cramps, and after the meeting, an elderly lady came to me and said, “You were having leg cramps, I could tell. Put a bar of soap beneath your bottom sheet, and
it will take care of the problem”.
I thanked her and thought, “Oh yeah, that’s gonna happen – sure, I’ve always wanted to sleep on a bar of soap! !”, but I have learned in my 81 years to discount nothing until it has been tried, and I also have the affliction of taking whatever I hear and trying to improve on it, so I asked my wife to take a potato peeler and peel strips from a bar of soap and put the shavings beneath the sheet to see if it would work, and she did and it did . . .
I found, though, that the soap took care of nighttime cramps but did little for daytime episodes, so I reasoned that perhaps a topical application of lather from the soap would work, and it does ! !
Use warm water, lather up your hands, and spread to lather on the afflicted areas, and DO NOT dry or wipe off – it will feel yucky for a few minutes, but IT WORKS !
Even after strenuous work like climbing a ladder and painting trim, the leg muscles
feel knotty and are telling you, “Just wait, Dummy, you’re gonna pay in a minute !”, and an application of the soapy hands will soothe and relax the muscles like oil calming the water . . .
It isn’t psychosomatic, either, for my wife poo-poo’ed the idea from the start and she got a cramp in her upper leg, inside, and was flopping around on the floor like a carp in the bottom of the boat, and I got the soap, lathered up and spread the
soap on while my wife was telling me to stop that foolishness and help her to bed, and in less than 1 minute she said the cramp was gone, totally.
I don’t know if the brand of soap makes a difference, but I use the Ivory bar soap.
geezer, are you sure the cramp didn’t go away naturally? Or perhaps the massaging effect of applying the soap helped? In any case, I’m glad the cramp went away. 
I am a science guy at heart, so I didn’t believe that the soap would work. But I really needed something to help my restless leg, so I thought I would give it a try. My wife told me I was ridiculous. I agreed, but I wanted it to work enough that maybe the placebo effect would work. So I tried it and…
It didn’t do a darn thing. 
I did discover that taking a single Aleve before going to bed helps. At least that is medically-recognized treatment advice.
I take iron pills and Requip and still have issues from time to time. When I can tell that I’m going to be twitchy, I put on a pair of diabetic compression socks. I find that their constrictive nature help my calves get the “feedback” (don’t know how else to describe it) that they need and they settle down.
I haven’t seen the feeling described as perfectly as you just did. I haven’t been diagnosed with RLS or anything, or even brought it up to my doctor, but once in awhile I get that feeling. People tried describing it as “skin crawling” or “urge to move” but those descriptions never hit the nail on the head for me. Feeling like your legs need feedback (or maybe just stimulus) comes a lot closer as a description.
When it happens to me (very infrequently) I fall asleep exhausted, because I’ve been rubbing my feet against each other with so much constant heavy pressure that the muscles start to fail. If I stop rubbing them, the most uncomfortable feeling creeps over me, like my calf muscles are being deprived of something vital.
Thanks for mentioning the compression socks. I always thought it was the MOVEMENT that helped the feeling, but now I see it might just be the pressure that’s helping. If it works, you’ll be my personal hero.
I tried that bar of soap in bed therapy when I had leg cramps, back in 2004 when astro first mentioned it in the OP. Today, I don’t have cramps at all!
Works like a champ, I say!
What you’re describing sounds like RLS to me!!
And massage or other stimulus is indeed a good, though fleeting, treatment. My blessed husband has spent many hours massaging my legs so I could get to sleep. I wound up getting a percussion massager a few years back and would sometimes use it to pound the sides of my legs until they were nearly numb, and that would interrupt the sensations long enough for me to pass out.
A hot bath can interrupt things long enough (even after you get out of the tub) to fall asleep.
I’ve never tried compression stockings for this, but people report that those inflatable cuffs they put on your legs in the hospital (that periodically inflate / deflate) can be helpful. I do know that direct constant pressure on my legs does NOT help.
RLS is neurological, so I guess anything that distracts the nervous system briefly can help.