Let’s be real, teens, especially males, will actively search for porn. Blocklists can be pointless, because even if you can blacklist 160k pornhub clones, they can just join a discord or telegram server instead.
Frankly, I think parents should just make them aware that just like cinema, those videos are for show, not for “trying at home”. Parents should tell them that if they ever expect sex to be like in the porn they consume, they’ll be sorely disappointed. Most of it is faker than reality tv. Oh, it can also make boys get really fucking insecure, especially about their own size.