If someone can't even understand how porn might be misogynist and abusive, I think they must be a lost cause. Preferably one I'd try to lose, IMHO. It's a bit worrying and disgusting that he can't even see the possibility of how it might be bad. Surely the very fact that the women in porn do stuff, or have stuff done to them, that the majority of women outside of porn don't must point to it being an abnormal and negative choice to 'consent' to.
There was an excellent documentary on Ch4 a few months ago, called something like 'Date My Porn Star', or similar, and it took 3 men who loved porn and thought the same things about it as your husband. By the end of the experience, the men had been crying, had been sick, and were thoroughly disgusted, shocked, horrified and ashamed. Even one guy who insisted he was still cool with it admitted in the 'several moths later' interviews that it had totally changed his thinking about it. And this was not the secret, extreme end of porn, either. Perhaps you could find this online (4OD) and ask him to watch it.
Tonandfeather makes an excellent point: studies done on the backgrounds of women in porn consistently reveal that they have been abused as children and/or raped as adults or had very sexually abusive adult relationships. If someone's sexual boundaries and sexual identity has been consistently and profoundly damaged and weakened, they are not capable of making genuine, informed, positive consent. Just like some women who grew up in households where they witness domestic abuse will end up in abusive adult relationships, thus some women who have been sexually abused will end up in sexually abusive jobs.