I have suffered on and off from athlete's foot between the little toes all of my life. For many years I kept it at bay by rubbing surgical spirit on it daily.
For some reason it came back with a vengeance about 8 months ago. I tried all the normal creams that the doctor could give, including Lamasil, and also Grisiofulvin spray. While they mostly kept the infection at bay to a greater or lesser extent, it would end up with thick, smooth white skin between the toes, with the fungus still alive underneath.
For a while I tried neat cider vinegar applied directly and while this exfoliated the thick skin quite successfully, it did not cure the condition. Then eventually I started to paint the infected area with a 1% solution of potassium permanganate (a very effective, old fashioned remedy that doctors in the UK are no longer licensed to prescribe) and after 2 weeks the athlete's foot has gone totally from one foot and has nearly gone from the other.
EC: More info: http://en.wikipedia.org/wiki/Potassium_permanganate