Needy Teton owner

Over the years our windows have become very hard to open, it seems the window and rubber channel have become very sticky, I have tried removing the window channel, washing it, cleaning the glass. (I did not remove the glass from the frame) I tried to purchase new channel at RV places & the internet, The Teton manual does not have the name of the window manufacture. (The window channel is 3/4" wide and the glass is 3/8" thick) Has anyone experiencing this problem and how did your resolve it?