Feeding Frozen Foods. . " How to "

I feed my fish allot of brine shrimp in addition to garlic pellets. I buy the brine shrimp that is frozen into little squares. I used to take a cup of tank water and throw the frozen cube into it until it thawed out. Than I would pour my cup back into the tank. Lately I have just started to plop my frozen cube right into the tank and just let it break apart on its own in the tank. Is there any reason I shouldn't keep doing it this way ? ? ? my fish don't really seem to care either way. . .