I can't help you, but will be watching for the answer as I'd also like to know how to handle the smudges.
Just to share what may be helpful to some about regular cleaning:
We have one of those upright vacs that have a long removable hose...sometimes called a "drape wand". I've purchased a separate, long and soft-bristled brush for that vac for cleaning my production equipment (getting in-between sliders on mixers, etc. can be frustrating otherwise! I simply marked the brush as "Equipment Only" and keep it with my cables, etc... It ensures that I can vacuum all my electronics without fear of using the regular vac "brush tool" that is used in all sorts of really dirty environments. Three bucks that was worth it!
Another thing I've done fairly recently is to buy a real feather duster... it's a "Texas Feathers" brand that I got at Home Depot. Maybe this was obvious to everyone but me, but I typically cleaned furniture with a furniture polish and glass/equipment with Windex. I had never owned an actual feather duster....at least not in the past twenty years!
Anyway, this thing really attracts dust like a magnet, is soft on the equipment, and with it's extra long handle, reaches the back of the top surface of my equipment!
