Great idea, Donald, thanks. Is there a particular product for head cleaning solution that's out there?
Beats me -- my experience with Canon printers ended when a BJ-330 (tractor feed, B&W only) was current technology. I do recall they use separate heads and tanks, unlike HP, and Lexmark (and Epson?) that include a replacement head with each new ink tank.
Are Canon printers still thermal (i.e. they form a bubble by local boiling to create the ink droplet)? If so, whatever you use needs to match the boiling point of the original ink pretty closely (I recall Parker fountain pen ink didn't work at all well in my BJ-330). I'd suggest contacting Canon or the various companies that sell ink refill kits to see if there's a special head cleaning cartridge or refill available.
Failing everything else, it'd be tempting to try 409, straight from the bottle...