Well I walked up to the local store to buy a can of WD40 and have a chat - and did they have a great old school trick to fix things once and for all. Basically they said the Silicon I used was a polymer - so it will never completely dry and hence it will always stick a bit. Any grease or spray I put on would need continual re-coating and would trap dirt and grime - cause nothing sticks to silicon...
Except bee's wax! They said get some good old fashioned bee's wax and pour it ever so thinly around the Silicon and it will grip and seal it and the rubber won't bind to the Silicon or the wax. What makes it even sweeter is my wife's hobby - making bee's wax candles
It all works unexpectedly well. One tiny candle later and its good bye grip! Can't believe how high tech and old school bee's wax sorted things - I am stoked!
PS
Tested it again this morning - works beautifully!