At my work any electronics that have had a water bath or flux-added rework will get an ultrasonic alcohol bath and then a forced air drying run. Alcohol is just so damned good for so much.
A few companies do make ultrasonic cleaners that are designed for flammable solvents, but they aren't common.
The easiest option is to just fill a plastic food bag with solvent, throw your part in, seal it with a clip and float it in your ultrasonic bath. The bag contains the vapour for safety, and it's easy to switch between different solvents and solutions.
That is next generation sous vide. Just controlling temperature is ho-hum. Getting it to just the right ultrasonic vibration to "cross-modulate the adipose frequency" is next level.
Even more spicy is vapor phase cleaning... evaporate the solvent, condense on the part to be cleaned suspended above it. Very effective since the impurities are constantly distilled out.
I've used both EtOH and propan-2-ol (IPA) for decades in ultrasonic cleaners both at room temperature and heated (quite warm to feel but not boiling hot) and never had a problem with fire.
Typically not (though some have heaters you can apply) but they atomize the fluid pretty well. The tiniest spark (static electricity) and some bad luck and you have the lid shooting into the roof and then a fire. As with everything, if you know what you are doing, go ahead.