Clindamycin is indeed an antibiotic used to treat bacterial infections. And 89Mirageman is correct, it will enter the body and the bloodstream through the skin. In fact, research has said that when something is rubbed into the skin as opposed to taking by mouth at least 40% more of it is absorbed into the body. All it’s going to do is kill off any beneficial bacteria you may have, making it that much easier for the Candida albicans infestation to grow.
If I were you, I’d ask this doctor if he knows anything at all about fungal yeast infections.