Large slide sticking to seal issue

We have a Outback 300rb TT with a 20' slide. Purchased 3 years ago, the slide leaked from the top outside where it meets the inside pillar that runs the length of the slide. So, dealer resealed it with caulking and it worked. The issue I have is that to this day, when the slide is open, the caulking sticks to the rubber seal and when time comes to bring the slide in, it forces the motor. I thought maybe to spread some sand on the caulking, maybe put a strip of duct tape over it... Any ideas?

Also, is there any preventative maintenance to ensure a long life to this massive slide? I regularly grease the ratchet gears (?) underneath.

http://www.campingworld.com/rvsales/travel-trailers/2015/keystone-outback/346880/

Love the Outback 300rb, but always thinking about that slide.

Oldcow