Nope, no scat for me, thanks.
With pissing the argument could be made either way, but it's not outright obscene (by the legal definition). I believe scat has been ruled to be obscene, so listing it would be like painting a target on your forehead. Bukkake is just a more extreme form of cumshot, so that's no danger.
Above and beyond all that, I have no desire to review sites with people shitting on each other. That's too nasty even for me.