I used Hylomar on the valve o-rings for years, and when I ran out and couldn't find more I just started dipping the base of the valve in ND-30 oil to lubricate the o-rings before reinstalling. There doesn't seem to be any difference at all in the life of the o-rings; if anything they last longer with oil. As far as the high pressure seals, I tried Hymolar on a couple pumps and had to pull one apart a week later for a different problem. There was no sign of the Hylomar ever having been applied to the seals, and I packed it in pretty thick.