Toilet gasket not holding water. Need a temporary fix.

I turned off my water, cleaned it, got some plumbers grease from Lowes and it stopped it leaking for a while. Camco sells a liquid that is supposed to help recondition the seal. Mine has always leaked since MH was new. Changed gasket and corrected it for a while. I think Thetford just builds junk. I am about ready to replace the toilet with a Dometic unit. Several have posted on here that the Dometic is a much better toilet.