From a regulatory standpoint, soaking a carburetor in Berryman B-12 Chemtool Fuel System Cleaner (part #0101) is an off-label use that may or may not be legally permitted in your state. If B-12 Chemtool Carburetor, Choke & Throttle Body Cleaner (part #0117) is approved in your state, then 0101 would be also be permissible. From a safety and functional perspective, however, using 0101 is not ideal. The product is extremely flammable and volatile, which can be quite a dangerous combination if not stored tightly-sealed. The best bet for small carburetors is Berryman Chem-Dip Carburetor & Parts Cleaner (part #0996), while the most appropriate product for 4-bbl carbs and other large parts is Professional Chem-Dip Carburetor & Parts Cleaner (part #0905).