There are lots of posts here on poison ivy that may be able to help you:
Homemade weed killer: Add 1 cup of salt, 1-tablespoon of dish soap and 1-tablespoon of vinegar into a gallon of water for a DIY weed killer spray that can kill poison ivy over time. Water method: Boil water and drown the roots in the hot water. This process can kill aggressive ivy but will take time.
Hey Chloe, do you mean 1 gallon of vinegar?
This one will for sure!