[gearhead]

Use the Protect All on the seals. Clean the exterior sidewalls and the exterior floor of the slide out with a bit of acetone on a clean microfiber cloth. I would test a small spot first to be sure you won't damage the finish with the acetone.
Then get the WD40 Specialist Dry Lube with PTFE doesn't attract dirt or dust, spray that on the bottom of the exterior floor. Then slip the WD40 nozzle spray tube between the exterior floor seal and the floor, and spray into the area that the slide retracts into. Spray into the width of the floor.
***This is assuming you have the exact same slide construction that I have.
Let us know how it responds.