I keep hearing about ice fishing with a dead stick. Anyone ever used this method?

I have. I normally drill 2 holes. I put one "inactive" bait down 1 hole(the dead stick) and then use my active bait(jigging spoon or jigging rap) down the other hole. On wide transducer, my vex will pick up both baits. Sometimes fish will race up to the active bait, but ultimately you will see the dead stick rod tip go down slightly or the line go slack as they actually take it instead.

I dead stick a rod every time out using an Okuma Ceymar Baitfeeder spinning reel that features a secondary drag. Allows you to close the bail on the reel and adjust the secondary drag to keep a lively minnow from pulling line yet light enough a larger fish can run with the bait with little resistance. A partial turn of the handle switches the drag to the primary allowing you to set the hook and fight the fish.

I've heard dead stick referring to live bait on a stationary rod(or tip up or rod trap, free line or set) to fully stationary lure/bait. The idea is to have a very neutral presentation for fish that may be very inactive or for pike that are very used to scavenging "dead" fish floating mid-column in lake. Taken many fish thru the ice with this presentation of many species. Works best for me on those days of extensive pressure changes when others are saying "there's just no fish in this lake".