Has anyone used these laser lens cleaners? Memorex Lens Cleaner at CompUSA I remember using one of those cleaners (YEARS ago) for my set top CD Player...It was the kind that you put a solution on the bristles and it spun around and cleaned the lens. A tech friend told me the 'liquid' ones may do more harm and he suggested just the ones with the brushes on the disc. Any thoughts on these? I just had an issue with a DVD Burner (at work) where it appears the lens may have been dirty and wouldn't work. I suggested (to my supervisor) that we look into a lens cleaner, but I wanted to get some thoughts if these are really worth it or not?