Some people laugh, but I had it done on my 3-inch GP several years ago & it does make a difference.

I even tested it with half a dozen or so .357 loads in the dark. With today's flash-retardant powders, you may have to try several commercial loads, but in some the muzzle flash was no issue whatever.

I don't find it a bad idea at all & my spare 3-inch GP will also have it done one of these days.
Denis