What ever you use should not attack the material being cleaned. I've used PERC, TCE, MEK, alcohol, Brulin etc depending on the situation. Read the msds sheet before use and there are likely safer chemicals. (some people should not handle sharp objects or throw caution to the wind) Suspend parts so they don't touch the vibrating walls/floor of the cleaner. Like others have suggested there are easier and more effective ways to clean parts.