Hi,
To your question, I have never kept Channa micropeltes, but a lot other snakehead species. And ALL of my channa eat dead food.
Its prettx easy, starve the fish, and then feed dead food (start with whole small dead feeder fish, or prawn), If the fish refuses try again next day, and so on.
It took me nearly a month to train a pair of Channa stewartii to feed on pellets. But it worked.
Cheers