Now he tells me!
While a few looks through the 17.5 inch scope might be interesting, you'll probably get the best views of a comet from a high quality set of astronomical binoculars.
Thank you for the information and advice. It is just after 40+ years of observations, which include two or three dozen comets; it is too late to change. In my defense (specializing in globular clusters and anonymous galaxies) most of those comet observations were unplanned and, obviously, extremely undesired. Although that doesn’t make it any less embarrassing to learn that I have been doing it wrong all these years.
I don't see why you should be embarrassed (or think you were doing anything wrong). It's just that if you want to enjoy the best views of this comet when it is at its most spectacular (presuming it will be as grand as hoped), your dob has way too narrow a field of view to encompass a significant portion of the comet in a single frame.
Why too late to change? If you don't want to buy a quality pair of astronomical binoculars, I'm sure there will be lots of outings where people gather to watch the comet. Find someone who has a set of Fujinon 16x70s on a parallelogram and have a look through them.