egg has to be hard boiled.. really cooked.. not half boiled as it will thicken the tank water like how it is used to thicken soup..
Boil the egg.. remove shell.. remove yolk.. chop white egg into bite size.. that's it..
you may feed the yolk to fishes too... but in bite size.. and the setback about yolk is cloudy water.. yolk clouds water badly and if not cleaned, the water stinks badly.. but u may consider using yolk jus before you are about to go for a major 50 -70% water change.. but it is the protein we are drawing from the egg white that is helping the fish to grow.. thus we only want to feed white without yolk..
drawbacks??? no no.. if egg is not boiled or poached.. then it is bad for your fish.. are you going to feed your fish a sunnyside up or fried egg wit bacon??

the oil is going to kill them!!! so boiled egg or poached is good.. but hard boiled egg retains all protein better than poached.. and we only want the white....
BUT!!!! there is a use for the yolk.. if you have fry (baby fishes) they are best fed with boiled yolk... yes.. how can I forget.. haha
and yolk can also be used to breed sea monkeys too.. very good source of protein for fish too..
otherwise, yolk is a NO NO.. White is a YES YES..
hope it helps..