Did have one once, and the solution chosen was a four-foot declaw--something I hate with a vengeance, yet it was the right solution for this cat and resolved the problem. Just trading one kind of pain for another, I suppose, but less muss and fuss.
Chronic fungal infections are a sign of systemic immune system weakness. Sometimes they are related to diet; high-starch and sugar diets seem to feed fungi really nicely. I'd consider really working on her diet with supplements to strengthen her immune system: antioxidants, Omega-3 fatty acids, enzymes, probiotics. See
http://www.littlebigcat.com/index.php?a ... atsanddogs for detailed information on these.
There are systemic antifungal drugs but they are expensive and/or have some pretty nasty side effects, and you have to give them for many weeks. Maybe not quite as bad as the foot-soaking? Hard to say!!
Cheers,
Dr. Jean