Cleaning

Not sure how dirty your watches get but I use a baby wipe first and dry with a soft microfibre (akin to the ones they give with glasses but less satiny).

Depends on what you mean by "glass". Toothpaste isn't going to have much (or any) affect on sapphire or even mineral crystals. It does work reasonably well on plastic/acrylic/hesalite crystals, although not as well as Polywatch.

Microfiber for daily smudges.  Dish soap and a soft toothbrush for regular deep cleanings.

Sandpaper and a wire brush. 

If needed use an angle grinder to remove extra tough dirt. 

(This is a joke. Just use water and maybe a toothbrush.) 

I clean more modern watches with a tiny drop of dish soap and cold water on a soft bristle brush..if I have any vintage ones to clean I take that said brush and get it wet let it dry for a few min and use your finger to flick a tiny spray of water onto the watch and wipe it down with a micro fiber seems to work great for vintage ones..

I wash any watch not on leather under the tap with whatever soap is at hand, hand soap, dish soap, whatever, often when I wash my hands. This includes the 30m water resistant Grand Seiko. Since sapphire is all but scratch proof, if smudges bug me aside from washing, I wipe it with napkin, shirt sleeve, whatever. No need to get precious about it. 

spit and my shirt

toothepaste (baking soda) works a bit like pollywatch

it'll buff out slight scratches 

back when we had cds toothpaste and a buff could get a scuffed up cd to play

Varies by whats getting cleaned and how nasty it is. A lot of watches that I buy to refurb/repair and resell have to be disassembled and detail cleaned and polished. I often make use of my ultrasonic cleaner to expedite the process.

Polywatch is great for polishing acrylic crystal. I've never attempted the cerium-oxide mineral crystal polish process but I will one day.

If I'm not concerned about water resistance Ill bathe it in lukewarm water with dishsoap and clean with a toothbrush. I use cool water and minimal handsoap for plastic cases, especially vintage plastic.

Thank you for listening to my TEDtalk

I use wristclean. 
1. Spray

2. Brush

3. Rinse

4. Rinse w/filtered water (prevents hard water spots)

5. Dry