Liberapay might be such a "buffer" too but technically it's not allowed either:
"Can creators of NSFW content use Liberapay?
The payment processors Liberapay supports have unfavourable policies towards sexual content. PayPal requires pre-approval, and Stripe prohibits it entirely. So, while it is possible to use Liberapay for some adult-only content, it is usually better to use a platform specialized in such content."