That crap is disgusting, expensive, and potentially dangerous. This thread gives new meaning to the phrase "kill it with fire".
I've had my share of ringworm infections, but lamisil always works for me. 3 days off and the **** is dead and not contagious, the lesion just takes about a week or so longer to heal completely. Of course I never let the thing get out of control beyond about 3/4'' in diameter. Oh, and it came from a doctor that 3 days of lamisil would make it not contagious. I've never seen anyone I've rolled with come down with it after me either.
Whenever I have a rashy looking thing I just bring a little cup of bleach into the shower with me. Wash as normal, then rub the bleach all over my body or rash looking areas, let it sit a minute, then rinse off. Do that a few times and nothing will survive.
If I know for a fact I have worm, I kill it with bleach, much faster than creams and stuff.
Everyone I know grows a vagina when I tell them I use bleach, but it works right away if you catch it on time.
Also, I love summer training because after every session I just jump in the pool and soak for a few minutes. The chlorine kills everything.