Have you ever rigged a double tailed grub sideways to represent a  swimming baitfish instead of a craw?  As in with the curly tails pointing up and down instead of side to side.  What did you think? Not as an alternative to standard flat rigging, but as an additional option to make the bait more versatile when efficiency is important, and as an alternative to other, more conventional swimming baits like flukes or single tail grubs.  I could see it working behind swim jigs, spinnerbaits, even buzzbaits for a high-action trailer for mimicking forage fish.  What about other craw lures like beavers or punch craws, etc.  These look great as bluegill or shell cracker imo.

Yup, I rig all my grubs like that on swim jigs/bladed jigs. My favorite is a C&C Big Head Wobbler tipped with a rage menace. 

When fishing swim jigs in milfoil I used some sort of Yum bait rigged sideways and it came through very cleanly and the fish seemed to like it.