I don't think the microwave would heat it up if there is no moisture in it. I was hoping that the microwaves would destroy any bacteria.
Using a conventional oven is also an idea.
I know UV light is supposed to work, but I've seen politicians walking around in the full sun, unaffected, so I'm suspect.
My grey came from the rescue with a homemade toy that was made out of small plates, the same material as egg cartons. He ignored it for a while, but once he decided it was safe (a month-long process for a grey) he really enjoyed tearing it up.