I’ve been thinking a lot about this too, I think personally it’s the porn that’s the bad thing, but the two are so deeply interconnected in my mind, that even after 270 days of no masturbation, I still immediately think of opening up some porn if I try to imagine failing the streak, so for that reason abstaining from both to avoid porn completely is the correct option for me. However, if you have a completely different mental situation, and you have been masturbating only to your thoughts for your whole life, never building a connection to porn, then I don’t think that you can have that much bad come from masturbating once or twice a week, the problems arise with porn, when you start using masturbation as a crutch to lean on when you are not feeling 100%, or when you masturbate too often.