So if I understand you correctly, you want to work your abs 5x/week?
Anything I've read states that, like any muscles in your body, abs need some rest too. Also keeping in mind structured reps and good form. 100 crunches in bad form won't do anything. Also, diet is just as important to abs as exercise. Takin' off that extra "layer" will start to reveal those muscles.
I do 3x20 ball crunches, 3x10 (50,60,70# pyramid) upward rows in my standard workouts 3x / week. I also try to keep my knees slightly bent and abs tight-in during any standing lift - that way the abs are always being worked, even if it's only secondary.