The less you touch that oring the better. More cameras have been flooded due to oring fondling stretching them out than any other cause. A camera housing back seal is a compression seal and thus needs NO Lube. Wipe it off with a microfiber cloth if dirty and otherwise leave it in place even when stored.
Removing it all the time just stretches it, and if stretched it must be replaced.
The manufacturers of my housings, both Aquatica and Subal, call for the use of, variously, Cristolube or silicone grease for the port and main body o-ring, static seal or otherwise; so too their removal for long term storage:
"The sealing surface and the O-ring should be thinly greased with Silicone grease. This reduces friction and abrasion and allows the O-ring to settle into place easily. Do not use too much grease . . . The O-ring should just have a sheen.
"Please note that the especially soft quality of the original SUBAL O-ring material loses elasticity prematurely if it is permanently compressed. So, if you plan not to use your housing for a long time, remove the O-ring and store it in a cool place without deformation."
I have never had an issue with any of the housings . . .