Twin Wasp - yes i think for the flight review the less the better, citing the reg is a good idea as anywhere, but like i said - AOPA has suggested to simply write "flight review completed satisfactory" which is actually very similar to what DE's write after a checkride, i.e. "private pilot ASEL sat." And yes, with regard to keeping record of endorsements I've fallen back on simply taking pictures with my phone or asking students to do so and send me them if I forgot.
OnCenterline, I actually have followed almost that exact same procedure since I started CFI'ing. Everything except having them sign it, but that is a good idea. Something I will consider in the future.
Thanks for all the answers.