Well it has worked for years with us, just take a bar of Fels napha, suds it up and put the lather on the poison ivy and let it dry, after couple of batches it'll dry up and be gone.
I got poison on my arms almost 2 weeks ago. It just seemed to be spreading and spreading. Then I remembered reading on here about the Fels Naptha and decided it couldn't hurt to try it. Well, it has helped tremendously!! and my poison has started drying up. The skin is a little flakey around those areas but the rest of it is ok. I scrubbed the areas with the wet bar, then rinsed well. Last night I was able to remove the coverings I had on both arms so it didn't get aggrevated by any accidental touchings on anything. I will definitely remember this for the future. Normally I would not have gotten it this badly as I thoroughly wash with lots of soap and water after being around any poison, but I was away and didn't do a thorough enough washing. Just had to share!
You wet the bar of Fels Napha and then rub it across the poison Ivy. This causes the Poison to dry up. I do not think you would have to wash your clothes in it,you should be able to wash them in what ever you usually use for your laundry.
I cannot answer your question, but Mary Hunt just had a recipe for soap in a column a few days ago. She is the author of "Cheapskate Monthly". I am sending you the link and I imagine if you ask the question there, she can answer you.
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