RE: Cleaning radios....
To clean those nooks and crannies on your TX, get a soft painter's brush.
Then fire up a vacuum cleaner and put the nozzle close to the TX as you brush off the dirt and particles with the brush.
The vacuum sucks up the now loose dirt, preventing it from getting inside the gimbals, etc.
I then we a towel with windex to clean the surfaces of what remains.