The ONLY solvent that should be used for removing flux residues from the surface of the parts being brazed is HOT WATER. The hotter the water, the better! The ingredients in flux are such that hot water is highly effective at removing all of the flux residues left on the brazed surfaces, and no other chemical ingredients are needed in the cleaning baths. Therefore, they are NOT recommended. The only time that any additive helps with flux removal is when the flux has been grossly overworked during heating and turns to a hard, dark-black, glass-like residue on the surface. Under such circumstances, certain proprietary chemicals have proven effective as additives to the water used to remove flux.
Just a reminder: The exact chemistries of each manufacturer's flux are their trade secret. Prior extensive testing has shown that these formulae are completely acceptable for use in brazing items used in a wide range of applications – from medical to industrial – if the flux is appropriately cleaned from the surface of the parts by using hot water.