I always silicone up the side windows. It keeps them from burning out the window motors.
The worst stuff is some pine sap getting into the felt the window rubs against. That will cause a lot of extra friction.
With the widow down, just run some water (from a sponge or similar) against the outside inner door where the felt is.
Not in freezing weather obviously!!
Or, in any weather, some RainX on a cloth forcing that fluid into the felt.
The windows wil lslide MUCH better.
The fluid will smear up onto the windows a little the first few times. but your window motors will last forever...