best time i've experienced was a opener in SAK . they were bunch up below eddy falls feasting on the walleye spawn drifting out in the current. when we realized this we put the smallest piece of a twistertail on a bare hook(only had yellow) and just let the current take out the line and they would suck it right in .
definitely a different and timing type of application ;) but we batter fried them and they were excellent !