The original question concerned cleaning the grips sir. Horn grips will absorb the natural oil from the neats foot and bring back the color from an old, dry gray appearance back to a very dark, black appearance. It will also help loosen any dirt and when the excess oil is removed off from the grips, they will appear very clean, and maintain that darkness for a very long time. I have been treating my grips in this manner for about three years now and they have not returned to that dry gray color.Collagen won't replace keratin. Soaking the grips in neats foot oil probably won't hurt them but won't do any good, either. You could go to a barber shop and collect hair clippings (keratin) and soak the grips in hair water for a while and it won't do any good either. I can't think of anything that will refresh horn, in fact. If anyone does, I hope they'll post it here.