Then shouldn't you be sticking with the first floor with the maze? You can test all you want there, and it's not as if you'll run into any Chimeras unlike the other floors.

[ Like the floor they're on. ]

Attacks from Personas are the most efficient. Though they can still be killed otherwise, as you have seen. You can tell your Persona to attack, or to do something... perhaps you can ask it what it can do and it'll tell you in your head.