there's so many things wrong with this thread.
first, reptile guy, that's a load of bull. live foods do not make Oscars more agressive. live foods are wonderful for them, but you are right in that live feeder fish should be avoided, but ONLY because they can introduce diseases to the tank, and because sometimes they will escape, and then you end up with another fish in your tank that you might not have wanted.
however, its wonderful to feed Oscars live earthworms, crickets, meal worms, etc. all live foods should be free of pesticides and chemicals like fertilizers.
SECONDLY, a 55g is the BARE MINIMUM tank size for a SINGLE oscar. Sharpie, you keep saying "OscarS" in the plural. not only is a 55g not large enough for two oscars to swim and have their own territory, the bioload would be incredible. you'd be doing water changes every other day, and not 25%, but more like 75%. the amount of nitrates they would produce would be phenominal.
unless you WILL upgrade when they are about 5" long (that's about 5 months) do not put two oscars in a 55g.