Honestly, here's what I would do. First, one hive isn't likely to make 21 splits, but if you have several hives you can take the queen, two frames of rbrood and two frames of honey and put them in an eight frame box (or ten frame box) with whatever you have, drawn comb is nice, foundation is ok, foundationless is ok if you have comb guides. Then in nine days make several more of these splits from your other strong hives, and maybe one or two more from that hive each with a frame that has a queen cell, a frame that does not (if there are any) and a couple of frames of honey). Now you've only made ONE hive queenless to get several queens instead of several hives queenless to get that same number...