What are you using in the ultrasonic?I can still smell the can of Berryman that it took forever to get rid of two years ago. I got a steal of a deal on a parts washer, but it came with the carb cleaner or no deal.
Carbs go into an ultrasonic cleaner now for my use. It's way faster and every bit as good of a cleaner, if not better, than the nasty stuff I used to use.
Simple green diluted to about 30% and maybe 1/2 teaspoon of Dawn detergent.What are you using in the ultrasonic?
The jar of parts is a good trick. I failed to mention that one.
Put plain water in your ultrasonic cleaner and whatever cleaning solution and your parts in a jar and submerge the jar in the water. The ultrasonic waves will penetrate the jar and you don't have to clean gunk out of the machine every time you want to put it away.