The mention of ozone gave me the idea to try Ozonol, a Canadian ointment I've been using for scrapes, cuts and burns since childhood (a long long time ago :-). After showering I applied it on the toe nails that had been discolored by fungus for years. Within 3 days all the discoloration (and soreness) disappeared in the lesser affected nail and within a week the nail that was more affected was cured also. The active ingredients in Ozonol are Phenol and zinc oxide (what they have to do with ozone I don't know, but it works!).
Walk on Wet Grass in the Morning
I haven't used this myself, but a lot of guys swear this works. This way to cure foot fungus was used in soviet army. Early in the morning take a walk on a grass while it is still wet, barefoot, and do this for a week. Fungus will be gone. This works on early stages of fungus. Scientific explanation for this is simple: As the water evaporates, a part of it makes ozone, which fights fungus.