What Does A Non-odorous Crumb Like Substance On The Vagina Indicate?
Need internal per speculum examination
Though you have mentioned that no smell or discharge I suggest you to get a speculum examination to rule out internal infections.
If nothing, try wearing cotton briefs and wash vulval areas with lactic acid containing solutions like V Wash.
Avoid using soap inside the labia and keep it dry to avoid moisture.
You can also try applying anti yeast ointments twice daily.
Hope you are not diabetic?