Hey, so my manual sliding door is sticky. Shop keeps telling me to just spray stuff on it but the wife and kids are having a helluva time trying to open the door constantly despite that.

Any tips? Ideas? Should we just replace the seals?

Just as the shop said you will need to spray with silicone lube which you should do yearly to maintain the rubber. You should also use silicone lube on the sides where your windows go up and down to keep the rubber/felt in there pliant and save the longevity of the window motor.

Use a silicone spray because it is less likely to attract dust. But like anything try not to breathe too much of it. Keep the kids away and don't do it in a garage.

I work in foam insulation, for 13 years I worked in R&D. When we make foam (thermoplastic) it is very similar to foamed rubber like your seals. One of the chemical components in rubber/plastic is plasticizers. These are what modify the softness/elasticity of the rubber/plastic. They bleed out over time from exposure to UV light and oxygen. The silicone spray or any other lubricant swells the rubber/plastic back up and fills microscopic voids that soften the rubber/plastic back to where it needs to be (never as good as new but still acceptable).

https://en.wikipedia.org/wiki/Plasticizer

Hello.

On my 2012 grand caravan, I use food grade silicon spray.

This stuff ensures the rubber gaskets stay pliable and will not stick to the mating door frames.