I'm very early in my rebooting process, like a week and a half, and only today have I gotten flashbacks to porn. It's fetish porn that I was hoping to get rid of from my life for good. Is it normal to have these flashbacks and have an urge to PMO again?
Employ a bit of mental fortitude to stop or ignore the images. Do NOT entertain them. Some people like to shout "NO!" in their mind, or visualise a big red cross and a klaxon sound. They're perfectly normal, don't let them get to you, and don't entertain them.
Yes I'm the same, though two weeks in and I'm already seeing less of them. I think it's natural and as Promise said, as long as you don't dwell on them I'm confident they'll start to disappear, or at least not flash up.