“... it might provide a little opportunity for them to learn something”
I don’t think liberal types ever really LEARN something; however, my concern would be “what do they learn about YOU”. For example, if you open your fridge and they see a beer... possible alcoholic? If they ask to use the restroom and somehow the medicine cabinet door open revealing a prescription... drug user? Is there a hunting/outdoorsy type magazine in plain view... gun owner. A few dust bunnies in the corner... filthy house? A person’s home is their HAVEN. It is theirs and theirs alone and it usually reveals more about the individual than you would expect. No way, no how, not in a million years would I allow entry. IMHO.
I have no problem with your point of view. I just don’t care WHAT anyone sees of my house (not that we have people over all that much). They WILL see a few dust bunnies, my wine rack and our reading materials, lot of conservative stuff and Bibles and commentaries, Sunday School materials.
However, I agree that should be the parents’ call, not the teacher’s.