Have you given klarstein a call? Their customer service is pretty good and they have helped others out I know with issues, after the warranty period is over. Let us know how to get on!
I have to be honest, I've not seen silicone rubber used in seals very often. Most products I have bought come with the advise to use food grade lubricant, which is silicone based, as opposed to petroleum based. Bungs on the other hands, lots of those are silicone rubber, apart from the ones I've ever owned, which were all normal rubber... lol
So, crazy idea, advise the OP to find out what the seals are made out of, then recommend the correct lube for that material? Otherwise, you could be advising one that will degrade the seals.