Tom,
While in FL this past winter we did use the silicone srpay and also tried a silicone grease. It did work but did not seem to last too long. Since the Thetford brand was on sale we thought we'd see if there were any different results. The Thetford brand has a consistency a little thicker than water. We let it sit for a couple of weeks and what a difference in operation. The blade really closes smoothly with no hesitation. Admittedly, when in FL we couldn't let it sit for a couple of weeks for obvious reasons. It would be interesting to see if other brands, sitting for a long period would also work.
Sue