I've never heard of varsol. If you use carb cleaner where you soak it in it, if left in too long it can remove the Teflon paint coating on the throttle shaft(s), and remove the gold iridited cad plating on linkage etc.
I just add like a pint or two to a gallon or two of fresh solvent so it doesn't permanently 'dry out' the bakelite bowl, and tear up the skin on your hands, too.
