I'm not looking to sell the product. In fact, I just did some searching and it's already for sale on Amazon as Dr West's Poison Ivy Wash. Dr. West (now deceased) is the inventor of the patent mentioned on this thread. He was a chemistry professor at LSU.
He uses Manganese sulfate. All the testimonials are favorable, so maybe it really works. At $15 for a 4 oz bottle I'd rather mix up my own.