I too use the retractable dog leash instead of a rope. I didn't know anybody else but me had thought of that.
It's great because you don't have anchor rope all over the floor of your boat.
Instead of log chain, I use a 22 lb. crab claw anchor like this:
They will dig into the bottom and hold you in position MUCH better than a long chain. If it will hold my Gheenoe in current with two people, I guarantee you it will hold a canoe. The crab claw is the absolute best anchor design I've found for holding the bottom securely.
The only time I use a chain is when I want to continue to drift, but I just want to use the weight of the chain to slow my boat down.
bd