Some time ago I read an article about how the mirrors of large observatories are cleaned professionally. There was also talk about a method of applying polymer films to the optical surfaces and then peeling them off. This is also possible for amateurs!
If you want to set up the mount in your observatory in a perfect and stable way, you will very likely reach for the steel column from Baader-Planetrium. This has a practical storage table, also made of hard metal - if you ever have bumped your head against it, you know what I mean.
Usually I am not in the observatory when I take pictures. All the more I noticed on the weekend how much dirt has accumulated in the observatory and on the dome over the winter. So give me the cleaning bucket!
For the CCD Workshop 2019 in Stuttgart, I was happy to give several talks.