Regarding Bell Hammer Gold, when cleaning motorcycle brake calipers, will it damage the oil seals if I apply it to the caliper piston and rub it out?

Please be assured that our LS Bell Hammer Gold will not damage the seals.
We also recommend a combination of silicone grease on the seals and LS Bell Hammer Gold on the pistons. The silicone will make the seals glide and the LS Bell Hammer Gold will make the pistons move.