We've been towing our 2009 Odyssey four down since buying it new, specifically for that purpose, despite the lack of official factory sanctioning. We've follow the warmup procedures shown in previous posts religiously, repeating them every four or five hours of towing. No problems whatsoever.
It is a HEAVY toad, though. I've been doing this a long time and never felt the need for a braking system with our previous (much lighter) tow cars, but I'm glad we got one for the Honda. We have the SMI Stay 'n' Play, which was a little more expensive than some of the alternatives, but i like that it uses the power brakes of the Honda, is effortless to use, and works great.