Never heard of them - I suppose it would be easier to just feed them strips of market fish every couple of days, when they get to that size.
I keep mine in an unheated tank, so the water is probably mid 60's. I have NO desire to experience "drastic growth" - I want his growth to be natural, and healthy.
He eats anything now - but is favorites are leftover meats and fish from dinners. His staple diet is still large Hikari and Ken's pellets, with some FD Jumbo Krill - all of my fish get a very varied, mixed diet.