I normally melt the WW myself. Normally I can separate the zinc WW before melting. If one slips by I just scoop it off with the slag because they float and melt at a higher temperature. Unless the zink has alloyed with something in your lead I think it would separate and could be scooped off the top with the other sludge. When I melt my WW ingots in the casting pot I also add pure lead and flux the mixture to get the hardness I want and scoop off any slag that forms.
Seams like once we the people give what, at the time, seams like a reasonable inch and "they" take the unreasonable mile we can only get that mile back one inch at a time.
No spelun and grammar is not my specialty. So please don't hurt my sensitive little feelings by teasing me about it.