Soap encapsulates dirt, or oil, or really anything that’s less polar, and then allows it to be solubilized in the more polar water layer. The first step of every place I can find for dealing with poison ivy is “wash with soap and warm water”.
Huh?
If you have been exposed to poison ivy you want to wash it off as soon as possible. Wherever the oil has landed it binds to and you want to get any not yet bound oil off you before you touch it and spread it elsewhere. Immediately washing off with soap and water is key.
The reaction to the oil bound to the skin is delayed. A few days typically. Showing up first where the load is highest, then other locations where it was spread to before washing with soap. It isn’t being spread at that point.
I liked the way my Granny smelled. And she was ancient.
Cancer at the end. I could smell that on her. It wasn’t unpleasant just different.
When Lumē tells me my Granny stank, it pisses me off
Life smells. Bodies can just do so much. A good wash with your favorite soap oughta be enough, daily.
I promise, @ThelmaLou I would not find you offensive if you smell like a human being.
It’s ok.
Yes, but with something that cuts through oil. Regular bar soap will push it around making it worse. Use isopropyl alcohol or a dish detergent like Dawn that is designed to cut through oil.
There is no evidence that any soap works better for poison ivy exposure than any other. They all have the surfactants that work on the oils fine. As quick as possible is the key. Bar or liquid doesn’t matter.
Also, it’s helpful to use a washcloth, along with the soap and water. And then wash the washcloth.
Anecdotal evidence that soap works:
When i was a baby, i went crawling through a big patch of poison ivy. My father took me out. My mother washed me, and my father washed himself. Except he only washed the parts that he realized were exposed to poison ivy: his legs, his hands, his arms. He didn’t think that I’d held onto him with my arms around the back of his neck as he carried me to be washed.
I didn’t get poison ivy. And my father only got it in patches on the back of his neck, where my grubby little hands were.
Speaking of smells, in a really stupid moment, i decided to try to kill a poison ivy plant with boiling water. I was enveloped on the scent of cooking vegetable. It smelled really good! And i was terrified I’d get poison ivy in my lungs. Thankfully, i didn’t. I may have never been sensitized to it. Or maybe the oil didn’t volatilize, despite other stuff obviously being carried by the steam. Anyway, I’m not going to try that again.
That’s simply not true. Dish detergent is used to clean oil from animals exposed to petroleum oil spills. Not hand soap, dish detergent. It’s designed to break down oil. Hand soaps are generally based on plant-based oils or animal fats.
Isopropyl alcohol works well for breaking down oil so it can be washed away. It was used for years in hospitals so it’s not toxic for such an application.
nevermind.
Next time kill it with fire! Or nuke it from orbit. It’s the only way to be sure.
Boiling water? That’s for sissy plant-sympathizers. 
I know that people have been seriously injured from inhaling smoke from burning poison ivy. So please don’t kill it with fire! At least, not around me. Nuking it from orbit probably works fine; everyone close enough to be hurt by the volatilized poison ivy is already dead, and can’t mount an allergic reaction. 
OK; I bow to your expertise. Time for compromise: kill it with Roundup. That shit always works. 
There are so many plants out in the wild that will cause skin irritations and itching.
I was helping my son work on his tomato bedding plants today and I was itchy up to my wrists. Okra does me the same way.
I had a kiwi the other day that made my tongue itch.
We fight the ivies and poison oaks and sumacs. Plus stinging nettle, some kind brush browse with purple berries, and even pine tar from a pine tree can make you have a burning sensation. Wisteria burn is real. Every year. Til we get tired of it and tell the kids “you know what hurts you, don’t touch it. And don’t step in that fire ant hill, barefoot, again…”
Nature will naturally kill us all.
I told you to get offa my lawn!
Well that’ll get rid of any smelly old folk, certainly…
The other day I saw a “humorous” sign hanging in a tourist schlock shop at the beach.
The picture was a skeleton on a surfboard riding a large steep wave. The caption was
EVERYTHING will kill you.
So pick something fun!
It is nice to hear a voice of reasonableness here from time to time.
Don’t listen to him, sir. You’ve got an enchanting musk.
I will always have a bottle of tecnu in my house or packed for an outdoor trip it is hands down the BEST skin cleanser for exposure to PI or any other itch causing vine/plant. I will not mess around with hand soap and water, give me tecnu stat.
But back on topic, look tor hypochlorous acid spray, keeps musty fusty smells away.
Oh, my god, thanks for mentioning this!
My poor little dog, a low-to-the-ground dachshund, suffers terribly from poison oak every time we visit a friend who loves to let him romp around their place. This is exactly what we need, as I see it is safe for pets, too. And it’s made less than 100 miles from home! Just ordered some!
I’m aware of the nonenal odor, have smelled it since I was a kid and continue to smell it now – even on me and in my own home. Didn’t know there was a name for it, though, so thanks for fighting my ignorance, @ThelmaLou! I’m clean, bathe regularly, clean clothes, etc., but it is nonetheless there on me and most everyone I know who is older.
I’m not bothered by it unless it is made especially intense by poor housekeeping or hygiene habits. Then it gets a bit off-putting.