Fluid for ultrasonic injector cleaning?

I'm looking for info on fluid for (solenoid-type) injectors in an ultrasonic cleaner. Web says everything from water to gasoline to Berryman's to angel tears. Had some Berryman's on hand and did a little prelim bench clean, and it very quickly wiped the paint off -- not the end of the world, but I'd rather not re-paint 8 injectors.

Have you cleaned injectors in an ultrasonic cleaner? What fluid works and won't harm them? Prefer something available at a hardware or parts store.

I've used mineral spirits.

I've also used Seafoam.

I will likely just use "Injector Cleaner" next time.

The ultrasonic and the back-flushing work wonders.

Do you have a way to pulse them?

Thanks for the response. Think I might have watched a YT video of yours on this.

I'm still sorting a way to pulse them; will likely be janky but functional.

I've pulsed injectors with a spare injector plug and a 9V battery.

We picked up a missfire during an endurance race and traced it to a clogged injector,we pulsed it with a cordless tool battery while feeding it some random cleaner in the trailer.

 Worked and back in and no more issues with it.

I want to add but you likely know, just put your cleaner in a little glass with your parts instead of filing your whole cleaner with the fluid. We have a huge solvent one here at work that you could drop a few assembled carbs in at the same time and its the only one I have ever seen running full of cleaner. I have been known to pusle injectors with a battery in the cleaner as well. 

Also avoid simple green it can for oxides on some metals and it looks nasty. 

In reply to wearymicrobe :

I just read about using glass elsewhere, was going to use ziploc bags. 👍

As an aside, I rigged up a turn signal relay to pulse an injector (not willing to dig out a spare harness for 4 at a time). 9V thru the relay makes it go way too fast (buzzes); 12V gets me a couple pulses/sec. Need to confirm 12V is fine - some internet strangers say it's too much for the injectors... 

My injector cleaning machine buzzes the injectors pretty quick - it definitely buzzes.

Too slow, and the injector may overheat?