My 2 favorite bottom fishing methods for lakers:
1) Hanging something off my downrigger ball with 50 lb. test (piece of cement, sash rod...something you don't care about losing) so you can drag it through the mud without haning up your ball. Off the release, about 75 feet back, is a lake troll, 14 to 20 inches leader, and a sewed on frozen smelt.
2) Lead core, 4 foot leader, with a Sutton spoon "bouncing" or "yanking" it off the bottom. This is similar to the jigging but you usually are drifting with the wind or trolling very slow on calm days.
I've always wanted to try the method your buddies are using. The hangup was how do I keep my boat staionary in 100 feet of water without anchoring where I would be fishing. Apparently a large drift sock is the answer!