How Often Do You Wash Breeches?

I interrupt my - I'm sure enthralling - coverage of Rolex to ask: how often do you wash your breeches? I generally go with maybe 2-4 times a year because washing just destroys fabrics. I got into the habit with jeans - seriously, don't wash your jeans - and carried it over to riding pants. I also prefer denim breeches. And it does work. I've had pairs of breeches last me years and years even with intense daily use.

However, there is a dirtiness factor to take into consideration. As I normally just ride around my own barn, if my breeches are dirty, so what? But since I've been venturing out into public so much (clinic, upcoming shows, and endurance rides), I feel like I should have clean breeches. I bought three pairs of breeches at Rolex; two of them are nice breeches, not my usual tights or denim breeches. I want to wear them, but I also want to keep them clean and shiny. And I want them to last, so I don't want to wash them all the time. So I'm torn; I don't know what to do.

What should I do? What do you do? Any advice or anecdote would be appreciated.