Reddit mentions of Tec Labs Tecnu Original Poison Oak & Ivy Outdoor Skin Cleanser - First Step in Poison Ivy Treatment - 12 Ounce

You put it on after! If you think you've been exposed, you basically use it like a soap to wash off the oil. Works on clothing, too! :)

http://www.amazon.com/Tecnu-Original-Poison-Outdoor-Cleanser/dp/B000A7S3WK

Best option when you have a ground cover is to pull the weeds by hand. It's a cleaner alternative than messing with noxious chemicals. As for the poison ivy, that's a horrible plant to deal with, and that's where I usually make an exception to my no poison rule. Then I usually say "Nuke it from orbit." However, what will kill a poison ivy vine or brush, WILL kill the English Ivy, which negates your ultimate goal, keeping the ivy. CrAzY_fReD's idea of using poison on gloves might work, but this could still transfer to nearby plants (English Ivy) via leaf to leaf contact or by the poison spreading to the root and into the soil where it gets picked up by the English Ivy. Now if it's just a few poison ivy plants here and there, this will likely be ok, and the cross contamination will be minimized. If you have a ton of this crap, then you need to consider not using poison.

Best option: Pay somebody who is not allergic to pull out the poison ivy, wrap it in trashbags, and throw it away. Do not compost, do not burn it. I paid a local guy who needed a break $100 to do this, some of the best money ever spent.

Cheap DIY option: Buy a bottle of technu. Cover yourself in rain gear. Use rubber boots, rubber gloves, long sleeve rain jacket and rain pants, cover your hair with a shower cap. Think cheap CDC getup. Get a box of trashbags. Open the bag, envelope the plant in the bag. Dig around the roots with a shovel to loosen the soil, and pull it up. Close the bag with the plant inside. Do not use your own hands to wipe any sweat off your face, have somebody nearby with a damp handkerchief that has a little technu residue on it to wife for you. I suggest doing this in the morning before it gets too hot and when the weather has cooled of a bit. Work efficiently and quickly, and afterwards, immediately take a shower. I suggest stripping off outside, do not bring contaminated clothing inside. Use a lukewarm/cool shower and more technu to wash with. Soak contaminated clothing in a container with detergent and more technu, wash these items separately twice in the washer, and then do an empty wash with bleach to clean the washer. If it sounds like I'm paranoid, it's because I've had to do EXACTLY what you are doing, and I'm allergic as hell to this crap.

The best thing to do in every case is use a good soap and scrub. I use Tec Nu poison ivy soap. I think comparisons still show it's more about the abrasive scrubbing than the soap type.. but it's worked for me. It's more about just scrubbing the PI oils off than anything