huummm? I'm interested in more information about this? what exaclty are you using? feel free to pm me.
I assume you didn't read my posts, fungus is likely, but type of fungus is just as important in determining which medication to use, tossing just any medication at it is not the way to go.
Hit up your vet with a sample of the geckos shed, soaking water, and substrate. Maybe even bring the gecko. The vet will be able to identify the issue be it fungus or something else and provide a recommendation for treatment, and a solid answer to what is causing the problem.
You are not obligated to seek treatment there, if you wish, you can tell the vet you are going to seek out a second opinion.
Most fungus does thrive in warm moist areas, some do well in cooler temps. Its best just to identify what it is so the best medication can be selected to get rid of it.
In the meantime I'd move the gecko into an enclosure that is easy to clean every day. Sterile kind of clean, and maintain it away from any other reptiles and air ducts. Think quarantine.
Maurice Pudlo