Ultrasonic cleaner advice, for cleaning chains before waxing I'd like to avoid solvents, or use less solvents when I re-wax my chain.

Are there any features I need to have in an ultrasonic cleaner?

I've seen unheated 700mL cleaners for ~$30 USD and 2 to 3L cleaners with 80 degrees celcius heating starting at ~$90 USD.

My current chain cleaning process is 


Boil chains in some water and wipe the melted wax off onto a rag.
Soak chains in solvent and agitate. I always see some metallic particles in the solvent after I remove the chains.
Hang &amp; wipe dry the chains.
Soak chains in melted wax.
Take chains out of the wax pot when the wax starts to form a skin, wipe the excess wax off.


Could I get away with a cheap ultrasonic cleaner and pour in boiling water + maybe a little detergent instead of using the solvent I currently use to clean my chains?
Some notes from my experience:

If you are in a 220-240 volt country avoid the cheap Chinese cleaners, they are designed for 110 volts and remove a rectification diode as a hack to make it work on higher voltage.  This doesn't work well as the peak voltages are still higher and the output transistors fail.

Secondly, I found ultrasonic cleaning in just water and soap is nowhere near as effective as using a solvent.  I use kerosene, however its very smelly so I only use it outdoors, but it does clean everything well.

Lastly, I haven't noticed much increase in chain life vs just wiping with a rag and oiling the rollers.  Because of this I don't bother ultrasonic cleaning chains unless I am cleaning something else like a cassette.  My theory is the oil aids in flowing out contaminants in the rollers but I have no evidence to back this up.