2001 Convertible

Since day one (well, I bought it on day 1,253, so let's say from then) the windows on the doors have been slow. They do not go all the way down when I use the "top down" button (will go down when I use the door buttons afterward). I neglected to clean all the electrical connections when I had the interior torn apart, so I will go back and remedy that. But, I assume that will not fix the problem.

What, if anything, can I do? Some sites have mentioned White Lithium Grease. Others have specifically mentioned Shin-Etsu (similar product by Honda). Assuming I do need to lubricate; how should I apply it?

Thanks
MRR