What kind of system do you have on your slide outs? If it is a Schwinteck system you shouldn't use silicone spray. It will leave a residue on the tracks that will attract dirt. The dirt e.g. sand will eventually cause the gears that mesh with the tracks to malfunction. You need to use a dry lubricant
The key is to look for one that uses PTFE. I use Zep45 for my slides. I also use it on the underside of the slide that contacts the slide rollers as it minimizes rolling / drag resistance (since not all slides operate on rollers).