Why not try herbal pessaries? Each pessary is made with a base of vegetable wax containing various ingredients, depending on the infection being treated. Normally a recommend a course is 10 pessaries over a one week period. One to be inserted in the morning and one at night for the first three days, then one to be inserted at night for the next four days. This is usually sufficient.
Thrush is usually caused by the yeast Candida albicans. Most thrush infections can be treated successfully by pharmaceutical medications, but some strains of Candida albicans are capable of the phenomenon known as "phenotypic switching". This means that in the presence of an anti-fungal agent, either used topically or systemically, most of the yeast cells will be killed but a very small percentage will change their DNA or "switch" to a very slow growing form that is resistant to the anti-fungal. These will remain in the vagina. Once the course of anti-fungals is finished a very small percentage will "switch" back to the normal rapidly growing variety, and the thrush will return. By combining three different essential oils the yeast cells are exposed to a combination of different anti-fungal compounds which kill the slow growing "switch" types as well as the normal fast growing types, thus preventing reoccurrence of the thrush infection.