My two copper colored zinc pennies:
1) I would not attempt to drain my WH through the plumbing. There is an incredible amount of junk in there from gooey calcium to chunks of anode material. This will be sucked into your pipes and then blown into your faucets and toilet when you "water up" next spring. I always shut off the bypass valves before I drain the pipes through the low point drains and pull the anode on the water heater.
2) I always flush the water heater out with a water wand and then teflon the anode threads (after inspection for enough material for another season) and reinstall it. This keeps the threads from rusting and the anode still protects the inside of the water tank from rusting over the winter and keeps bugs from building nests inside the water heater.
3) Always use the teflon tape (or teflon pipe dope) on the anode to prevent the threads from corroding together with the tank socket. Use a 1 and 1/16th inch 12 point socket with extension to remove and install the anode. Yes you can use all kinds of make shift ways to get it out, but if you bugger it up you will be in a world of hurt getting it out after that!
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW