Yep I have heard of it. Basicaly it is a primative and inacurate form of fishless cycling, all the fish food is a supply of ammonia.
I think you will find a good majority of regular users of this forum use a pure ammonia source instead of fish food.
In my hummble opinion I see it allows for a more accurate dosing of Ammonia and possibly a much more efficent fishless cycle with much stronger and stable bacteria but then I am no expert on this matter.
I would always recommend a fishless cycle using a pure Ammonia (or as close to pure as possible) source as recommended in the beginners resource centre else were in this forum.