At least with respect to US federal money laundering laws (18 USC 1956, et seq.), there needs to be “specified unlawful activity”, as defined, involved for it to be money laundering.
Running a legal porn site isn’t illegal.
Running a legal porn site isn’t illegal.
I assumed that wouldn't be necessary if not operating like a business with the intention to turn a profit. If I sold my car for cash, would I have the same responsibility?