If you are into using sandpaper as an acceptable replacement for toilet paper, I guess you'd be ok with using an abrasive nutrient regimin on your ladies. With using those nutes throughout the grow...it's easier to create nutrient lockouts, overdosing, and it's harder to diagnose and correct problems...

I guess I'm saying...using the right tool for the job is a good idea. A 2 or 3 part nutrient regimin makes your life easier, and the plants will be happier and healthier.