The general Idea is not bad behind it,I would just worry about the stick hurting the fishes mouth in any way, just like you said. 'The way I make my koi food sink is, I soak it in water for 10-15 min (they are huge koi pellets and will handle that), then squeeze the air out and hold them in my hand, wh ile the hand moves slowly into the water. I do the latter part mostly to get my baby koi used to my hand, since the hand-food connection is the one that makes them wonna come. So far, it works...!