DVD lens cleaner.Which one to use?

I have a Denon DVD/DVD-A/SACD player.Which type and brand of lens cleaner will work well? Is it best to clean by hand or can a DVD cleaning disk be used? I am hesitant of using a $10 cleaning disk on a $1000 player.
You should never have to do this unless something is sitting right on the lens. The only thing I would recommend is a can of compressed air to blow stuff off. Never use anything else, especially anything that makes contact with the lens, like brushes, etc.
Agree with Shayner.
Do nothing unless there is a real problem.