I would say a gel type silicone, not a spray or an oil but real silicone. It should come in a round container that you can dip a finger into and then run around your seals. I looked for a link on line but could only find KY :shock:
go to a dive shop and get a little tube of silicone grease. normally used to lubricate o-rings on cameras and divelights, but would work great for this.
I bought a tube of 'gasket grease' from a local pool supply store. It is a silicone gel that I apply to all rubber on the boat. I lubed up the rubber gasket on the cabin side windows and it really helped stop any water intrusion.
Robin recommended vaseline to me and that is what I have used. I re-do them every 6 months. It has worked well for me. Having vaseline around is also good for abrasions, cuts, etc until you are able to get back to port.