I would think you should go with whatever the manufacturer of your slide mechanism says. Lippert says to lubricate the piston rods on our hydraulic actuators for both the slides and the levelers with silicone lubricant. I picked up a spray can of it at Camping World last time we were there. It's not supposed to hold onto dirt like some other lubes. They don't mention anything else in their documentation for our rig that I can remember. Of course your situation might be different.
I use dry teflon lube on our slide. I concur with Jeeper, use whatever/however the manufacturer of your slide(s) recommends. Our slide is electric, Jeepers apparently are hydraulic, so the recommendations will be different.
Salem 29RKSS Pushing a GMC Sierra 2500HD!
Gotta go campin!