Could work, maybe. I'd probably want facial expressions and body language though. The facial expressions of "I'm confused" or "I get it" are crucial. And the gestures of "we're both looking at this while I explain it" "now I stand up a little bit, want to give an example a try?"

Sounds dumb when written out, but the alternative is to keep asking "do you understand?" And then getting back "yes" or "(lying) yes," because nobody ever says they don't understand if the question is asked at them directly.