Hi screech! I will try to answere your question, but have in mind that English is not my mothertoungh
1. Yes you can put the complete bezel in the bath! I strongly suggest to do short periods because you really dont see the result untill you have
washed it. I used a glass and after appr. 60 sec, i start to fill the glass with water, use a lots of water. Try to avoid to touch the bezel until its dry. repeat if you want.
2. Pop of the bezel, cover the glass and the back! use "sticky tac" Im not sure about the English word but the type you can use for posters etc.
I also covered the space between the lugs. 1/ Put some coins and screws, nut etc. in a can. be gentle. 2/ Use the same can but put some round small stones instead. (same as used in flower pots) Strip the back from the sticky if you want some light "wabi" on the back... and shake it gently once again
Avoid to shake "up/down" try to move the can so the watch and stuff rotate together. Do you follow?
3. I didnt do anything specific to the he valve, it simply turned out that way during the abuse mentioned above
4. The Nato is grey from the beginning, but it