I’ve done this very thing with MgCl (magnesium chloride). I used to do the scratching method, but it left some scars where melanoma were scratched. Then I bought one of those pin rollers and the results were much better.
As an aside, the melanomas were popping up on my outer thigh in exactly the spot where my phone has been in my left pocket for many a year. Further, this spot was where AS CHILD I got sunburned over and over. Lots of folks probably have the line on their thigh where one day you wore shorts that were a little longer and the next a little shorter and got burned. Ladies may have the same problem on their bikini line. If you got second degree sunburn (blistered) as a child, keep an eye on those spots. They will likely be trouble later.
I guess keeping a phone in a pocket is a bad idea! Never done that, so I wouldn’t know.
I’ve never sunburned badly enough to blister. But there was a period of my much earlier life where I dwelled on islands with remote beaches where I camped out and swam nekkid and was tan without any bathing suit lines! Now that I’m a Floridian, I never quite revert to my au naturel pasty white (on my uncovered areas, that is LOL). So I never really even burn enough to peel anymore. I’m usually fairly tan by late spring just from my routine outdoor chores. That’s part of the reason I wanted all of those moles gone. That and the fact that they were an ugly nuisance. ;)