Be sure your life insurance is paid up if you're using non approved liquids in a sonic cleaner.....
Are you talking about flammable liquids or toxic liquids?
Specifically ones that break down and make toxic gasses. While not as readily available as it once was, Carbon Tetrachloride is what first came to mind. College chemistry classes taught that heated Carbon Tetrachloride was one that could break down and possibly form Phosgene Gas and Hydrogen Chloride. Cavitation bubbles in a sonic cleaner may increase the possibility. It's best to check whether the liquid is safe before using it.
