I don't mind NSFW artworks, but I could do without the NSFW tags. Even if they mean good, I feel like they're spoiling the comic somehow, warning you of something shocking ahead so you won't be surprised at all by what's coming to you. It already places you in a "get ready for some shit" mindset before any action happens.
I think that simply saying from the get-go that your comic's NSFW is the best solution, either by mentioning it on its first page or somewhere clearly visible on your website; but not letting every other page get some sort of narrative interruption.
I mean, what if we were to put NSFW tags before certain movie scenes? You're watching a horror film, and before the killer brutally murders a teenager, you get a 10 second pause to let you know the following scene may be NSFW. Thanks for that, lads, I was kinda feeling pretty horrified by this horror film. This is why we have Movie Ratings, to let you know what kind of movie you're gonna see before you actually see it, and I feel the same should be with NSFW warnings.