Well, my first pass at using o rings was a reasonable success. I originally thought with the recess cut to house the o-ring, all would be ok, but one has to be careful not to cut too deep to house the ring. If you cut too deep, the ID of the ring becomes larger than the diameter of the recess, so one has to be careful to ensure the o-ring fits snugly. I also had to cut a recess in the mating cylinder because I simply could not fit the mating cylinder over the ring with the o-ring size I had. One solution would be to use an undersized o-ring so that the ring is stretched a bit, reducing its diameter and making fitment easier. Will have another go tomorrow. Plumber's grease worked fine, but would prefer to have something with more lubricity.