Does anybody use an ultrasonic cleaner?

I got a DK sonic one, that was recommended on the silca podcast iirc. Get one with a bigger capacity than you think, especially if you want to clean a cassette. around 3l.

However after a couple of years I am not really sure they are worth it. Shaking a chain in a jar with cleaning agent of choice is at least if not more effective to prepare a chain for waxing, and clean the cassette with brushes, once you start using a waxed chain, you don't really need to clean cassettes beyond hosing the mud off.

Yeah I think outside of bike shops or someone doing several chains at once on a regular basis then it's not needed

Used one when I was preparing diving kit for high pressure O2 - any oil residue could actually make it burst into flames and kill you to death so stuff needs to be really properly clean. Biking kit generally doesn't need to be *that* clean so a decent scrub with degreaser or IPA is enough. If you want a mechanical clean then allegedly the household dishwasher does a good job.

 If you want a mechanical clean then allegedly the household dishwasher does a good job.

cough, don't tell the other half that's how the cassette got cleaned (but no longer a needed  method with chain waxing).

I bought one 18 months ago. I chuck my chain in it maybe twice a year with soapy warm water or a degreaser then I rinse it with warm water in the ultra sonic cleaner and it does a good job of cleaning out the very fine dirt which is hidden within the chain. 

Would I buy another if the one I have breaks? Probably, but I wouldn't rush to get one and I'd wait for a bargain buy.