It's bad but not for the reason most people think, the 'worse' thing is because you don't realize it's really a repetitive ACTION rather than a thing.
Thinking is an action, thought as a noun makes it seem like a thing. Your question, as is the case with most people when they think about this is framed with a noun. It may seem like semantics until you actually see how it influences your perception, it is a misunderstanding as to what is going on with the mind.
The good thing about the mind is you can always change your thoughts, unfortunately most people don't realize this in everyday life.
Here's a key distinction:
1. Porn content
2. Pornographic thinking
The first only involves an action to start streaming the data. The second, whether it's fed by current visual stimuli or just a memory (which doesn't even need to be visual btw) is what you decide to do with it. If you want to work on your mind at a deeper level, you'd be looking at changing the thinking process. Even if you're bulletproof with your blockers and just don't get any NEW porn content/input, there's stuff you remember and IDEAS, whether you've actually had that experience or not.
If anything I find identifying reasons why I'm thinking whatever PMO related patterns that seems to just pop-up in my head out of nowhere more powerful than just trying to block it out, and then also reasons for taking it in another direction. It makes sense to do that with content, but it is impossible to do that completely or even mostly with sexual thinking or actually with most thinking for most people - so it's just being realistic. But identifying the reasons let you steer it in a different direction. The more specific you are, and the more explicitly you state it (like saying it out loud to yourself or writing it down) the better it seems to work. So instead of something like "I'm stressed" without so much as identifying what is stressing you out like a job or family/relationship issue etc. do exactly that and say who at work or at home is doing what to stress you out. And that's just the first half, it can diffuse it a lot but then you can follow that up with reasons to take it in another direction. It can be as simple as "I know I'll feel better if I just get out of bet and start the morning than if I PMO and I'll end up with brainfog" etc. Again, spoken out loud is a good idea.
Repetitive thinking patterns that seems to have solidified into a "thought" is still just mental activity, and people basically just needs to get used to changing their thinking. Just because you're used to always taking the same route to work driving it doesn't mean your car can only take that exact route, you can take a different turn at any given time.
