When is it time to clean laser glass and what's the best method?

My Lite-On drive is several years old, and considering that dust has to accumulate in there along with particles of various matter from the disks, it’s probably time to clean the laser glass. Is it just a matter of opening the unit and using some alcohol and lightly dabbing it with a cotton swab?

I have a feeling these cleaning kits are too abrasive, if they’re anything like the old VHS tapehead cleaning kits. I’d like to clean my DVD player lens too, and I’m assuming the procedure is the same.

What do all of you do to ensure that the disks you place in the tray of your drive (before and after burning) are free of dust particles? I’ve heard of everything from using the cool setting of a hair blower to dusting the disk with cotton balls (I find that in warm, humid weather, there’s more static electricity that makes the cotton lint stick to the disk using this method).