To combine two threads here -- yeast infections and alternative
therapies -- I've discovered Tea Tree Oil (sometimes spelled Ti Tree)
is very effective for thrush.  It's one of the few essential oils
which can be applied directly to the skin without being diluted.

Place one or two drops on a lint-free cloth and dab the affected
area.  It can be used to swab the inside of the mouth as well (tastes
bad at first, but actually has a "just-brushed freshness" feeling
afterwards).  Also, a few drops in a glass of water for gargling
works well for sore throats and "furry" tonsils, too.

Purely my own experience, so try it yourselves before testing it on
clients ;-)

Jennifer Landels, BA, CE
Vancouver BC