Accidentally recorded with two microphones active. Can I salvage this?

You can reduce the hollow reverberation by mixing down to mono, removing as much bass as is acceptable to your ear, then using a (free) expander plugin, like Couture, to attenuate the reverb.

There are plugin$ like ACON DeFilter & ACON DeVerberate which allegedly can solve the problem,
but those cures can be worse than the disease, (see attached).