I have 508.24 as well and recently asked my local Meridian dealer what was the recommended method of cleaning the optics. He uses and recommends canned compressed air. However, I have used an Allsop Carbonedge Laser Lens Cleaner on a number of players including the 508 and it hasn't caused any problems. As a matter of fact it has helped with mistracking problems and improved the sonics in some instances. The apparatus is in the form of a compact disk with tiny carbon brushes attached to the data side. The one I have also has a track of pink noise for burn-ins, as well as other diagnostic tracks.
