I disagree with the lead comment. I think there are many, many more important factors dealing with waterfowl, with a much worse impact, than a few lead pellets in thier gizzards.(invasives, predators, oil spills etc.) Thats a whole new topic though, so I'll leave it at that!
You can't beat hunting late season divers over a spread of hand made blocks though, that I will agree on!!
We'll have to hook up next season for a shoot!
Good luck getting your info, the guy in the link knows his stuff!
S.