I do not advise to hammer them out, but I do this all the time (on a low grade russian bike from the 70's that is built like a tank, the BB is tough too, i never managed to break it by hammering without support - because i never had a third hand to hold the crank, hold the pipe and strike with hammer)

Most of the time a hammer solves everything with no harm* in less than a second.

*seriously do not hammer a top tier vintage rare bike and its cotter cranks, it hurts more psychological not that is likely to damage something aside aesthetics (if you miss) and a mangled cotter pin (if you're not straight on the blow). Use this on average-low beaters.

My 2cents: given the condition, use some sort of press if you have, or a bench vise if you have, or a hammer with a pipe to support the crank, (or without support but this can hurt the BB even if I have never managed to do so) - do not spend any money, use what you have and you can get your job done in a matter of minutes.