I finally got this to work for me. I ended up casting Burn in Turn 7, instead of swapping in frolicker. Then kept everything the same through turn 11. In Turn 12 Frolicker is swapped in. Turn 13 Scratch and Shadeflicker died.
Tested this a few times both ways and I found that both strats will work eventually, but it is important that the Corefire Imp DOES NOT die!
Full credit to gamerunknown on WoWHead. After over half an hour bashing my head against the other strats here, I checked there, tried his strat, and it worked on the first try. So I figured I'd put it here for others to make use of and hopefully not drive themselves insane.