I soak all my carby stuff in Threebond before putting them into my Ultrasonic with a mix of an Orange (Citrus) type concentrated cleaner, a little dishwashing detergent, water and Vinegar.
This is an Aussie link but it is the same stuff Subaru use to spray into the intake to clean their intake tract and inlet valves.. you would be amazed at how it brings up manky carby parts green from ethanol fuels etc.
http://www.threebond.com.au/aerosols.html