How about doing a pass where you categorize as in for sure, out for sure, and idunno. There may not be too many of those idunno‘s, so may be possible to enlist help.
That said your approach seems to have worked well. Kudos!
Yup, that's a really good point. I kind of wish I had marked ambiguous words on a first pass, and then taken a bit of a different approach for a second pass of just the difficult ones.