Well I have always used this method, which is using an Ultrasonic Cleaner that you use for jewellery.
I bought a cheap one of these a few years back now (from Ebay). Although it is not large you can still fit quite a lot of pieces in at a time and hey presto, it removes the majority of the dirt/dust for you. I use warm water with a little dish washing liquid then when they have finished in the Ultrasonic Cleaner rinse them under running water to remove all traces of detergent, dust etc.
I just let the pieces air dry on a towel which doesn't take too long and this has worked well for me over many years.
NOTE - To prove the cleaners do work, you should see the water left behind after a dirty model.. Cheers..