I will assume the poster you are referring to was talking about polishing the surface of the trigger face, where your finger rests. This is done a lot for those who do a lot of double action shooting, and/or speed shooting. The serrations of a trigger will irritate the finger in short order when doing a lot of double action shooting.
I have done this to three of my revolvers. 1. Mod 60, 2" that has also been hammer bobbed for carry, and therefore can only be shot as double action. 2. A Mod 19, 2 1/2" which is used for come carry. 3. A 686, 6" which I had used for steel plate competition.
You can do this your self. It is best to remove the trigger from the revolver first, so you don't accidentally nick up the gun. I put the trigger in a padded vice, and using a dremmel, grind the serrations down to smooth surface. Then with canvas backed emery paper, starting with about 80 grit, polish the surface and contour the edges. Work it down to crocus cloth and it will polish out like nickle and be very smooth.