What I mean is just, instead of only tagging #___ and #NSFW also tag #___NSFW. Treat this like a kink tag.
The big example I can think of is the pokemon tag. I follow the pokemon tag and have silenced most of the nsfwpokemon tags because I have a general disinterest in pokemon porn and it kinda tends to clog the pokemon tag. Even so, like 1/3 of the pokemon tag is porn that gets around my filter because the only way to filter it out by tags is to completely block pokemon or nsfw content, which j don't really care to do.
(This is not a condemnation of pokeporn fans or anything, I just don't share the interest.)