unfortunately mold is only one of your problems. flood waters carry unsanitary things like ecoli and others bacteria's. it should have been washed down immediately. your sandwhich walls may still be harboring some bad stuff.
search on killing black mold, you'll find mixture combinations of tide, tsp, bleach and water. all good. i guess i would try killing what i can reach, let dry. ventilate well. check with local authorities on post-flood conerns such as yours.
my parents lived in a flood zone for 30 yrs. btdt.