I've used the DIY trap without turning the top inside out like that. Tie fishing line to the big opening, float it kinda near the top, put food in the bottom, and wait for the target fish to swim in. Pull on fishing line, remove bottle.
I've also put food in a net in the tank. Takes a lil longer, but they can't help themselves. They swim into the net to get the food and you just pull them out.