I use those silicone baking mats a lot. I cast, reload and shoot my own bullets from lead alloy. I used to size and lubricate my bullets with lubricant in a metal die. A few years ago someone came out with a polomer paint that came in a powder form. You would put the powder, a few plastic bb's and your unsized bullets into a #5 plastic container and shake the container so the bullets would get a smooth powder coating all over. Then you place the powder coated bullets onto a cookie sheet and bake at 400 degrees for 15 minutes. The powder melts and coats the bullet evenly. Then if necessary you can size the bullet and then load it into your favorite cartridge case and obtain a completed round. The advantages obtained make the extra steps worthwhile. First the amount of smoke generated is diminished greatly, the gunbarrel is easy to clean since there is not any lead stuck to the metal, your dies do not get gunked up with excess lube and your completed round is clean, has wonderful colored projectile and is capable of outstanding accuracy.
I use the silicone mats under my bullets. The excess powder and dried polomer paint is easily cleaned off with hot water and a soapy sponge. The aluminium cookie sheets were impossible to clean up.