I have made a similiar training aid but by using a different method. I also took and old 5 iron and put a hole in the end of the grip at the top. Then I filled the whole club shaft full of BB's. Then I taped the hole back up at the top and there you have a weighted club. THe nice thing about this method is that the weight is uniform, all through the club. Pack them real tight and you don't even hear a BB moving around in there.

Chessbum...