I am not sure if the irs has guidelines for the adult industry but any reasonable expense will be justified.
Below are examples of expenses that you can write off against your content creator income.
You will use that account to take in your content creator income and to pay your content creator related expenses.
There are even free bookkeeping tools like Wave that make this super easy.
So like if you did your makeup for some extreme fetish thing, then cleaned it off right afterwards.
You will have to pay taxes as an onlyfans model.