Graphite doesn't react with much of anything except acid.

I used to use a product on my mointain bike when I lived in Arizona. It was called Dri-slide. It was a mild solvent carrier liquid with graphite suspended in it. You just squirted it on and it penetrated in. After a few minutes, the solvent evaporated and there was nothing left but graphite.

You could probably get the same results if you mix the powder with a little naptha... (found in the paint dept. at your hardware store.) Mix about 1/4 teaspoon with 2 oz. of naptha in a squirt bottle and shake it up!! Put a little down the edge of the window into the track, roll it up and down a few times and let it dry.

...I might have to try that just to see how good it works.. or not. Naptha and rubber get along well so it should be OK.