Yep, I’ve resorted to thongs too. To be honest, the longer shorts style undies work even better, but in super hot weather, they are just too hot! And cotton undies are the worse for chaffing - if you sweat, you will have damage.
As others have mentioned, start with position changes before looking at saddle fit. And yes, for some women, it is also just conformation - which means it really isn’t totally fixable. You may have to compromise on position a bit to make it work. But before you do that, do stretches, work with someone who is a biomechanics expert, become familiar with your pelvic floor, and if possible, borrow a few friends’ saddles?
I have to admit, I do NOT understand how this all works for men - it seems like THEY would have a huge issue - there is all that extra - junk - to rearrange? How did saddle fitters make it comfortable for them? But still not something that works for women?