I did some duracoat on some bolt actions I had here.
On the slide, make sure you remove all parts before starting. If you cant remove a part, ask here how to do it. Any places where the parts fit into, mask off before painting but after degreasing. I would not want to paint anything but the visible parts of the slide when the slide is forward int battery.
Brake cleaner is your friend. Spray it two or three times to get all the oils off the slide. 600 grit sandpaper everywhere you can. (Not the bolt face where the cartridge base seats or any sliding surfaces where the slide rubs the frame.) After you sandpaper, more brake cleaner. Then into the oven at 250 for 30 min to see if you can bake any more oils off it or out of the nooks and crannies. Once it cools, more brake cleaner to get the oils off that have seeped out.
***IMPORTANT*** Once you start using brake cleaner, wear nitrile gloves so you dont get any oils from your fingers on the metal.
Once you have this done, you can spray your parts. Make sure you do not try to get a complete cover in one pass, you will get runs. Many light passes, letting the paint dry for a few minutes between passes. It takes a lot longer to paint, but is a lot less time consuming than trying to sand out runs in the paint.
I have heard of silicon sealant causing issues with bubbling in the paint. As in "silicon sealant that is in a toolbox on the other side of the garage" causing bubbles. I took my parts outside and painted and let them cure dry for a few minutes because i wasnt sure if I had silicon hiding somewhere.
Thats all I got. Pictures are always enjoyable. Show us what you end up with.