Cleaning your watch isn’t as complex as it sounds. If you have a real issue with your watch – it’s running fast or slow or seems to contain water – you need to take it into a watchmaker. However if you just want to clean up your watch get yourself an ultrasonic cleaner.
I bought a $70 Chinese model on eBay but you could also get something like this Braunsonic. The cleaner vibrates a water bath which in turn creates tiny, energetic bubbles. These bubbles get into all of the nooks and crannies of your watch bracelet to pull out dirt.
The process takes about 15 minutes for a fairly good cleaning and you may need to clean dirtier watches a few times. My Omega Seamaster had a few clumps of grossness in the case and a run through the ultrasonic bath for about 15 minutes cleaned them all out. You can place any watch that has a depth rating of 30 meters. Do not bathe non-waterproof watches as the action of the bubbles could introduce water.
I sometimes drop a few drops of hand soap into the water for stubborn dirt but you can also try special soap concentrates.
For a small investment you can clean almost anything with this thing. Sunglasses, rings, necklaces, and bracelets all came out cleaner and brighter. Give your nicer watches a few trips through the bath and the machine will pay for itself in the long run.