best solvent for ultrasonic cleaning

I picked up an untrasonic bath today and will be using it this week for some carb and valve cleaning...what is the best solvent people have found? I have access to some strong solvents as I am a chemist. I was planning on using DCM but if you people know of some others that work well for gas gunk then that would be great!

ive always used the branson water based stuff. i dont think you want to use anything dangerous itll just evaporate into the air. the water based stuff works the nuts!! its not the liquid its the ultasonic action thatll do the job. oh and the hotter the fluid the nicer itll clean your stuff...post pics of your results

I tried removing the carbon on the tops of my pistons with carb cleaner and it didn't do anything...big waste of time. I am going to try DCM tomorrow, and if that doesnt work I will try this Branson stuff and or ask my tech if he has anything lying around that works....I am developing quite a respect for WD40 in terms of cleaning ability, it works great, and smells like candy!

I do not want to highjack the thread but would it be possible to expand on the whole ultrasonic cleaning details and equippment the only time i have seen it used was by a Tatooist that i used to visit about 20 years ago he used it to clean his tatoo guns

Regards Dale