Recently we had difficulty sliding our own awning along the rail, when it usually glides easily. We struggled to get the awning to the end of the channel, when out tumbled a pile of nut fragments! Apparently the squirrels must have been having a nut cracking party on our trailer, even though it is stored under an aluminum shed. Live and learn! So be sure to clean out the rail with a test tube brush and some soapy water. It is an easy job that will prevent a frustrating experience. If you have a vinyl welt on your awning, sometimes in cold weather Blaster Dry Lubricant can make it slide easier. The cold seems to make the welt stiffer and the aluminum channel contract, while during warm weather it glides easily. Recently at a Rally I helped another Rally participant set up her awning, which was very difficult to pull along the rail. Blaster came to the rescue!
We used to rub the welt with wax paper and it worked like charm, not enough build up to attract dirt but enough wax to let it slide easy. Also if you have kids or grand kids camping with you and the play area has a slide that isn't slippery take a piece of wax paper and let them sit on it and slide down a few times to wax the slide. May take a few sheets.