Yep, grapefruit seed extract obviously might be difficult to handle for some people. I thought it might be worth a try on a seriously steady soluble fibre base. I used it for several weeks not that long ago and didn't notice too many problems. But caution is best, as ever.
Tea tree oil is as gentle but powerful as you can get. I should, however, have suggested that it be diluted in warm water before you dip in the tampon and then insert. This is a tried and tested method for vaginal thrush. I've personally used tea tree cream and tea tree washes on a baby's horrifically sore nappy(diaper?) rash and a friend of mine's used the tampon method for thrush (it worked). Don't go mad though - it won't need several applications a day every day!! This is nothing like douching which is BAD as it's too harsh. This is just a gentle application of a diluted tea tree oil which will kill off candida but NOT the good bacteria that you NEED.
If you don't fancy trying the tampons, just try sitz or regular baths which can be just as effective. I would only try the tampon method once or maybe twice if I were in a REALLY bad way.
Hope this clarifies things - I should have been a bit more specific - like everything else. Just because something is helpful you don't have to go overboard. Less is more as they say. Let me know what you think.