OK, I’m a slob. I’m not proud of it, but I admit it.
I haven’t cleaned a tub in long time, and there is some really tough grime on it. A first pass with a supermarket-knockoff cleaner that contains bleach and a mild abrasive didn’t do much.
Anybody have some cleaning advice? Mods, if this is better suited for IMHO, I have no problem it being moved. But I suppose there is one best way to clean it, although a consensus might not be reached.
I would try Lime-a-way or CLR.
I saw this on a DIY program the other day: caustic soda, in solution, up to the rim of the bath for a day. It’s nasty, and you should have the doors closed and the window open - and you need to rinse the bath a zillion times afterwards to avoid getting burned next time you use it.
Bon Ami.
IF you have an old fashioned porcelain tub…Wet the tub, all over. Sprinkle scouring powder (NOT Bon Ami) on it, preferably the kind with bleach. Wait about 10-20 minutes, and then start scouring. Repeat as needed. This will scratch the tub, but it will look nicer than it did with the grime on it.
If it’s discolored, and a porcelain tub, lay paper towels on the stains, and soak the towels with bleach. Just pour the bleach VERY slowly.
Don’t mix bleach with ammonia, it creates a poisonous gas.
If you have a tub made of something else, I have no clue.
Seriously, lye and water?
… I wonder if that would work.
(my bathtub is really grimy, too)
Is it a Cast iron tub or one made from Fibre-glas? With the first, a sledge hammer is used, with the latter a recip saw is the best tool
Hey, you said ** really ** grimy 
Delta-9, does Lime-a-way and CLR work on dirt/grime? I thought they were best for hard water deposits and such.
jjimm, not sure how feasible the caustic soda is. The bathroom has no window, and is attached to the bedroom where I sleep. I suppose I could spend the night at a friend’s or something, but that plus the zillions of rinses makes it maybe too much trouble. Might be a good last resort, though.
There’s a product out there called Krud Kutter that works pretty darn well. Doesn’t smell noxious, either. If you can’t find it beside the regular cleaners, look in the Housewares department by the industrial-type cleaners.
I guess I should have mentioned what the tub is made of. Unfortunately, I’m not sure. It’s not cast iron. It’s not white, I don’t think it’s porcelein. It looks like the same material my bathroom counter is made of, it’s kind of an almond colored faux-marble type stuff. It seems pretty hard, and could probably withstand some harsh cleaning materials.
I’ve lived in grimey-ass bachelor pads before and i’ve never seen a tub that Comet couldn’t clean. You might have to gasp use some muscles but it works. 
…Or muratic acid… available at any pool store. Let that soak in for a while.
Are Comet and Bon Ami about the same? I seem to recall they being sold in similar containers, is one a knock-off of the other?
My Mom always used Comet, I guess that’s a good indication that it works. But she sure never let a tub get as bad as I got this one though…
Perchloric acid. Yes, that’ll do something for sure.*
Seriously, though, I’d throw some CLR or Comet on it first. It’s going to partially depend on what the grime consists of. You’d want to match the cleaner with the makeup of the grime.
*Perchloric acid is dangerous, highly explosive, and all around just plain nasty. The following recommendation was meant purely as a joke for anyone who knows what the stuff is like and is capable of.
Napalm.
Use CLR first and then go over the rest with Comet and or Tilex.
Then clean all the debris away with your bargain knockoff cleaner and hot water.
I believe Comet has bleach or more bleach than Bon Ami.
The natural solution is a paste of hydrogen peroxide and creme of tarter and some scrubbing.
Comet is washing soda and chlorine bleach. Bon Ami is soap and feldspar, a mild abrasive. Much better.
My tub has been nasty looking since I moved in - I don’t know what the person before me did to it, but it’s never really looked clean (I scrub it once a week).
I set out a couple of weeks ago to make it white again, dang it. So I took my shower (figuring that’s a good way to make sure the surface is wet) and sprinkled it with Comet once I got out. Let it stand for two hours and started scrubbing. It still doesn’t look clean. I’m at the point where I wonder if it’s a white finish over something else, and if the finish is wearing off in places.
I just use “Vim”. Wet the tub a little, then squirt the stuff all over and let it settle for 20 minutes or so - don’t let it dry, because then it’s just as tough to remove as the dirt! Use a scouring pad (I use the synthetic ones, not the metal ones) and scrub away! I used to have a REALLY disgustingly grimy housemate, and one shower from him would put more dirt into that tub than my SO and I have added to it in the past month! (To give you an idea, he used the same towel for 6 months, and to my knowledge only did laundry once - that towel wasn’t in the laundry load).
Anyways, if Vim can get rid of his dirt and the hard water stains from the hard water in this bloody city, then it can probably clean your tub. You’ll need a bit of arm power, but Im a totally weak female, and even I can do it, so I’m sure you can manage!
If you scratch the surface using an abrasive cleaner, it will be a lot easier for “new” grime to attach to the surface, which will require more cleaning, and more cleaning, and more… 
You get the picture.
If the surface already is “destroyed” though, you will probably not do much harm, if you use an abrasive cleaner.
Yep. My experience with using Comet and similar harsh abrasives, and with using chlorine bleach, is that they etch the surface and it then gets dirty/stained much more easily. Bon Ami is much less likely to make the problem worse.