As with most things, it's situational.
If the passage is relatively soft, I'll just use the wood of the my very expensive antique bow. I'd like to think I have a pretty good idea of what I can get away with (force-wise) without damaging anything or leaving a mark.
If the passage is louder–and it affords me the time-I'll flip the bow around and do the tapping with the button. Sometimes I'll just smack the string against the fingerboard with my hand. Sometimes the sound the composer really wants is the "clack" of the string against wood, anyway.
If it's just a huge loud passage where a million things are going on at once and it's almost more visual noise than anything else (e.g., the Carl Ruggles piece I played over the summer), I just mime it. Haven't been called out on it once, and even had a composer commend me on my nous after a concert.
I don't have a beater bow, per se, but I do have a modern bow where I'd be less heartbroken (and financially ruined) would it be damaged and I do sometimes use it for programs with more, let's say, robust passages.
Any passages that require truly aggressive, forceful smacking of the strings with the wood of the bow I quite simply do not do with my bow. This is what drumsticks are for. I encounter this far less than I used to, but on the odd occasion that I find myself in a student composer reading session these days it does happen from time to time.
I don't have a carbon fiber bow anymore, but they certainly are a good bit more durable than wood. That being said, "more durable" does not mean "indestructible." The only bow I've ever broken was, in fact, one made of carbon fiber (a Robertsons-stamped Carbow). That was the day I learned that carbon fiber does not crack, but rather it shatters.
