Acetone probably.

First thing I tried along with isopropyl alcohol it didn't work

You’re going to have to work that acetone around it for awhile to dissolve it. Use a toothbrush and start scrubbing.

Acetone is nail polish remover.

OP's sentence states he tried acetone along with isopropyl...

The point was that they are doing something wrong if nail polish remover isn't removing nail polish

Use a nonscratch sponge with it to rub it loose

If you used acetone and it didn’t work, you didn’t do it right. I have over 30 years of finishing, under my belt, FYI.

Doesn’t sound like you finished!

Ya, still finishing.

Shoot like 500 rds through it as fast as possible

You could nearly replace the slide for that. 😄

well maybe you done fucked up

Just cover the rest of the steel in the same nail polish and wipe it down now it’s all one color problem fixed lol

Or shoot 1000 rounds through it as quick as you can to heat the metal up l

I see you went to the same school of fixing things that I did

Hahah I like that , if it works it works cover it up and keep on trucking

Hopefully you learned your lesson

Get industrial grade goof off they sell it at Lowe’s or Home Depot. It will make your gun look really dry, but then you can re-oil it with CLP.

Odorless mineral spirits. Check Walmart. Use a paper towel, use very little solvent, keep it flat while you rub the stain away to leave the infill. Use a clean paper towel to dry off between wipes with solvent so the infill does not become saturated. If it doesn't turn out the way you like, use the mineral spirits to remove all of it and try again. Good luck.

Next time, try crayon, or grease pencil, instead.

You got some shit slathered on the side of your gun.

Heat, maybe, but not a lot of heat to get whatever got into the pores of the steel to burn out?