Nope, it won't hurt anything if you don't use dishwashing detergent, or water. The detergent will cause the casting to floresce. (That's that white powdery stuff that looks like mold.)
What it also won't do is get the varnish and other residue out of the ports and channels.
Better to spend a few bucks on a can of carb cleaner than risk messing up the carb body.
