You can block the NSFW instances and domains as a start. It may not get rid of EVERYTHING, but it can help.
Examples:
https://kbin.social/d/lemmynsfw.com will take you to that domain. From there, you can hit block (next to the subscribe button) to block at the domain level vs a specific magazine. (NSFW instances are going to have lots of magazines in them so this is just more expedient.)
You can also block any NSFW magazines on Kbin itself by going through the magazine list and hitting block beside those listings.
This isn't specific to NSFW obviously. I only learned about it recently via a YSK post that likely does a better job explaining things, but thought it was worth a mention.