a) I'd love to see some AI that could better flag questionable pictures. That's an insane problem to crack right now though.
b) I pop open my pictures in windows explorer, set it to large icons and cruise through the folder ( NOT windows image viewer ). I can get through a lot very quickly. I get most of them that way. Usually the bad ones I miss are a one off in the middle of a sequence or a folder I just failed to scan through.
In your case, I believe you're using the phone app for a lot of them. That's not so easy to mass edit.
One possibility would be to dump them all onto a pc / mac, run through the photos and then upload them via the browser, the python script or just dumping them back onto the phone into the mappilary image folder. It's an extra step but it could help catch the obvious stuff.
How did Google's Panimora [sic] handle bad images?