I used to work on Argon Lasers a long time ago for shows. We used Acetone to clean optics and it worked miracles!.
Is it safe to use Acetone with the optics in the GlowForge?
The way we used them was with a special optical grade swab, we impragnated it with acetone and then a gentle swipe of the swab while rotating thru the optic in only one direction with little pressure. It did wonders to grease and dust.
I’m not sure about acetone, however we used a mild lab grade acetic acid (purified vinegar basically) to clean the lenses on the Bystronic 3.5kw laser. We’d remove the lens, place it in a special holder that securely held it lay a lens cleaning wipe (just like the zeiss ones) on the lens, then drop 3 to 5 drops of acetic acid onto the paper, wetting out the lens. Then pull to the side sliding the cleaning wipe off the lens without any direct downward pressure on the lens itself in order to preserve the special lens coating on the optics.