Wow, you guys are faithful tack cleaners!
I take better care of my tack than anyone I know and I am not nearly that religious about it. The things I wash the most are cinches and saddle blankets. I wash them whenever they get overly sweaty/crusty. That means once every week or so in the summer. Saddles get done maybe 4 times a year, headstalls, reins and breastcollars only when I think they need conditioning. So maybe 4 times a year if they are lucky.
I actually never wash bits unless it is a used bit that I bought and I don't want to pass along germs.
I have friends that never seem to wash/condition anything, except maybe once a year when things are obviously crusty or dry.
Maybe it helps (or hinders?) that I am sort of a tack hoarder, so when I rotate though a lot of headstalls, bits, and saddle blankets not any one piece of equipment is getting used every single ride. So they stay cleaner longer perhaps?
PS. If I cleaned everything after every ride I would have little time for anything else. The clean up would take as much time as the riding I would think.