That 'net on a clip' idea was meant to serve the food over a longer period of time. It is clever IF the fish get the hang of it. If you only have one or two fishes eating this food, it may be hard to get them to come close to the clip. In my tank with many fishes there is usually one or two that are bold enough to come up to something new pretty fast after it is put into their tank. The rest follow.
Here's a couple of suggestions. One may work better than another, depending upon the quantity of food you have to deal with.
1. Take a still frozen cube and thinly slice it, then dice it into tiny bits the right size for those fish eating it. Ideally you don't touch the food with your bare hands. Let thaw and feed.
2. Get a small electric chopper. Thoroughly clean it, preferably never use soaps or chemicals -- just hot tap water and then plenty of rinses with distilled water. Put the container and blade(s) of the chopper in the refrigerator overnight. Take an entire container of cubes and let them thaw in the the refrigerator. While still cold, chop the cubes in the chopper. Put cold pieces into the smallest sealable freezer bags you can find. Freeze the entire bag(s). Take out the portion you use to feed and keep the rest frozen, let thaw the portion to feed and serve up the chopped bits like you would if it were pellets.
I've used graters, cheese graters and all sorts of contraptions, but in the end the electric chopper did the fastest and best job when everything (chopper and food) was cold from the refrigerator. You can control the size of the pieces of food by how long you run the chopper. So you chop less for bigger fishes that want big chunks; you chop longer for fishes that want small bits. If you have a mix of fish, then you can go half and half and blend the two before bagging and freezing. If the chopped food has too many tiny bits that the fish won't eat, use a cold fish net to 'sieve' the food while it is cold -- tiny bits go through the net openings and separate from the larger bits as you shake the net (best to cover the net with another net).
Set the chopper aside to be used for only this purpose and clean immediately when done using it (hot water; no soap; rinse with distilled). When it is dry, bag that in a sealable bag until it is needed again, then the parts go back into the fridge the day before you chop. Don't put the motor of the chopper into the fridge.
Hope the above helps.