I'm using gentian violet for thrush. how often should i use this a day and for how long?

Azole cream better: Gentian violet is an old fashioned, messy, and not very effective treatment for vaginal yeast (thrush) infections. If not professionally diagnosed, see a doctor. If you've had yeast before and symptoms are typical, try an over-the-counter yeast cream; look for active ingredient ending in "azole" (miconazole, teraconazole, etc). Any of these will be more effective and faster than gentian violet.