I've silvered mirrors using the technique described in the back of every old CRC Handbook (of Chemistry and Physics, of course). I seem to remember that is gives the procedure for taking an ammoniacal solution of silver nitrate (really oxide) and then reacts it with Rochelle salt. This solution reduces the silver and as it drops from solution, it can coat any opbect placed in it's way - mirrors, the sides of the containers, anything in there. It's not a very abrasion resistant coating, and when thin it can easily be rubbed off. It's been over 30 years since I did this, but I seem to remember that it also created a lot of sludge. I suspect that was some collodial silver.
One of the links I gave above gave Rochelle salt (potasium sodium tartrate) as one of the reducing solutions, so I'm sure the chemistry will be similar to that process. I think rock sugar can be used as well, as can formaldehyde and many other chemicals.