Le Guin pretty successfully wrote a whole planet of androgyns using masculine pronouns.

In Left Hand of Darkness, the narrator is an offplanet visitor and the only real male in the setting. He starts his tale by explicitly admitting he can't understand or accept the locals' sexual selves (they become male or female for short periods of time, a bit like estrus). He has to psychologically assign them sexes, but he can't handle a female-only society, so he treats them all as males. There are plot points where he fails to respond appropriately to the explicit feminine side of locals.

This is all very interesting and I liked the novel, but it's the opposite of passing androgyns as normal in writing a tale. Pronouns are the least of your troubles :-)