I don't. Never heard of it. I'll check the video out at home (can't look at youtube at school). I'm wondering what it does to the slides.
What I DO do, however, is grease them once a year -- meaning that I've done it once.
I use white lithium grease and simply spray it on the "cogs" (for lack of a better description. My repair guy said that it isn't necessary to spray the track/teeth, as spraying the cog thingy will coat the track as the slide is extended & retracted.
Mitch, $410 is about what I paid for mine to be purchased & installed. I was told that part of the cost depends on the length of the slide, so there might be a little negotiating room there. My slide cover was 12' long. If you don't have a ladder on your trailer to inspect the slide EVERY time you bring it in, I'd spend the money now and forget about it.
Laura