I ordered one of those Harbor Freight 2.5 liter ultrasonic cleaners. Searching the forums turns up some threads in which folks mention using diluted Simple Green and other types of solutions. But I did not see anything which mentioned using something like Finish Line degreaser.

Is it overkill, or would it be good?

Too, it seems that in every ultrasonic cleaner thread, naysayers (who might have never used one) abound. What do you use in your ultrasonic cleaner?