Rash Remedies

i'm allergic to a plant down here and unknowingly got in contact with it. i broke out in a really nasty rash on my arm and neck. A trainer at my gym told me to use epsom salt. He said it'll dry it out and kill the bacteria in it. i did and my rash cleared up in a few days and gott noticably better after each treatment. Mind you i tried all kinds of creams and allergy pills that had no effect what so ever.