You can laugh at me for this post.
When I clean my Form 1+ optical window, I usually wear a hat or shower cap, and wrap my arms in saran wrap (or wear a long sleeved shirt made of synthetic fibers). I’ve noticed it helps prevent dust, etc. from falling off me and into the internal chamber. When cleaned in this manner, my mirror is completely free of those last few specs that inevitably wind up on the surface if I don’t do this.
Just thought I’d share this tidbit in case it helps others. Or for folks who haven’t had a good laugh yet today.