It's a pretty darn good idea. Issue being, clients may not like their garments treated this way. Especially one client that uses fine lace and alike.
I'm sure there are ways to photograph these, whether it's on an mannequin, shot frontwise, then the inverted rear and merged together. Or shot on a fine wire rack which is cloned out.
This said, I don't believe it can be too time intensive as I've seen a local photographer offer this service at a fairly low cost. When you break that cost down into time, I don't believe it could be too complicated. It's just not worth it.