I have a 2001 Dolphin with a living room slide out & a bed room slide out. The living room slide out I can get to the gears to clean & lube. But the bed room slide out is covered up inside & outside...
On mine the box slides on some nylon blocks, I lube the bottom of the slide box with Mothers Carnuba wax.. That Paraffin wax idea might be as good or better.