Took a punt on a lidl special. .. 20 quid for a ultrasonic bath cleaner.
Checked out a few reviews online and seems to be alright.
Just done all my cams in a bit of warm water and a couple of drops of bike degrease stuff.
Bit of lube and they feel smooth as silk now. The bath bit is not that big .. about 14cm by 12cm and 4cm deep. Did the size 4 one side at a time.
Be good for bike bits, cassettes etc.
Think I might do my swiss army knife next which has a couple of decades worth of grit fluff and gunge embedded.