Without referencing any regualtions, the practice at least sure doesnt seem to make any sense.
Whatever you decide, make sure you get it in writing with a signature from the FSDO to back yourself up if it hits the fan.
Doubt airlines accept that as PIC time, though. Might even make them look a bit cock-eyed at you. Don't know how you can log PIC in 121 while not acting as such.
Best of luck man.
