I don't have a glock.
I use a dental rubber polishing wheels.
They are different colors for grit, white, green, pink & couple others, can't recall been 20 someodd years since I done that work, but the wheels last when taken care of.
It is used by dental lab techs for polishing dentures, crowns, bridges etc.
And can also be used with different styles of polishing compounds.
The basic wheel I use mostly is approx 3/4" x 1/8", but wheels come in various diameters & thickness.
It's mounted on shaft for use in the pencile size to dremel size style rotary tools.
You have to use a soft hand & keen eye when you use them to polish trigger & hammer surfaces, they will round a sharp edge quick & cause a dangerous hair trigger, and used too much take the hard face surface right off to soft metal.
Used correctly, with a soft hand & keen eye they will mirror polish smooth & slick like a lubed low friction high speed precision ball bearing.
You'll be surprised how smooth & easy even heavy triggers pull.