Thomas,
I had the identical same symptoms for over a year. Finally went to a doctor who took a culture. It came back positive for strep and staph. A perscription of Kelfex cured it...I would strongly suggest you get a culture done.
A rash on one foot only is not likely to be fungal. Added to that is the fact that fungal treatments haven't helped.
A toe rash which isn't fungus may be something in the eczema or dermatitis family. Soaking repeatedly in peroxide or alcohol is very much the opposite of what is likely to help. You don't need or want to clean your foot that often, since you may well aggravate the problem that way, and dirt is not the issue.
I therefore advise you to avoid repeated cleaning with solvents, to apply a healing ointment like Aquaphor (OTC) several times a day, and to deal with itch by using Sarna lotion as needed (also OTC.)
If after a few weeks of that regimen you're not comfortable, I advise you to consult a skin doctor. It's worth the price of a visit, I think, once confounding factors like irritation have been removed.
Best.
Dr. Rockoff