Rubberized stylus, not moving smooth on iPad glass, any tricks?

I have a Targus stylus for my iPad, with a rubber tip. This tip, however, does not move smoothly over the glass on the iPad, but seems to have too high friction. It didn't have this when I bought it, and I also have a different stylus that is much smaller, also with a rubber tip, that still moves smoothly over the glass. The large one, however, gets "stuck" on the screen. Not like glue "stuck", just doesn't move as smoothly as I'd like. What tricks can I use to get it back to how it was when I bought it? Has it accrued fat from my fingers or something like that I can wash off, or are there other things I can do? Has anyone experienced this and solved it?