I've never done it before, but I've seen some old antique tin minnow buckets with holes in them. I'm told that people would hook a chain to the handle and lower it down the ice hole while tying one end off in the house. Thinking about it, your minnows would probably keep alot longer. I've thought about trying it myself by using a smaller minnow bucket that one would tie to your boat. What stopped me was I figured that if you don't open the hole up for a couple of days and the weather is really cold, I would imagine it would take quite a bit of work with the chisel to get the bucket of minnows back up again!