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

1. Boil chains in some water and wipe the melted wax off onto a rag.
2. Soak chains in solvent and agitate. I always see some metallic particles in the solvent after I remove the chains.
3. Hang & wipe dry the chains.
4. Soak chains in melted wax.
5. 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?