I used them once last year when we were running out of leeches and I didn't get one bite on them. I thought they would work much better then they did However I should let you know I was bobber fishing and not jigging, so I haven't tried them any other way. just my 2 cents.
My buddy and I tried them in Colorado last summer, neither of us caught anything on them and we tried trolling, jigging and just casting them. I will tell you that if you spill that in your car (in the hot summer sun) you'll never forget it was there! lol
i used them last summer and had no luck with them in the metro area; however i used them on island lake, up north of duluth and was using a bober and was catching about 1/2 what my buddy in the front of the boat was catching, so yes they work up north, there was enough wind to jig it for us though and we used jigs on our bobbers.(probally helped walleyes were hungry!) Dosnt out fish livebait though, maybe for boundrie waters or somewhere your hiking in to?