I tried this once using cayenne capsules that I picked up in a local health food store. They were 40,000 STU's (Scoville Thermal Units) of capsicum annum - but I know that you can get even more powerful cayenne at something crazy like 100, 000.
I'm not sure if the addition of the cayenne made a huge difference or not but it definitely made me SWEAT. Give it a try bro.