Is it common to travel by giving private lessons at host family?

So, a while back I had this idea, to make travelling a bit less expensive, by giving private lessons and tutoring in target country.

In summary, I travel to a target country, stay with some family, they provide food and place to sleep and in exchange I give private lessons, probably to the kids, probably in some school subject.

My question is this. Is such a thing even heard of, and if yes, how to begin?

Did You hear of someone who did something like this, how did it turn out?

Maybe there is some website that will help or people use Couchsurfing website to do it?

Note: I'm asking mostly about Central Europe, but feel free to say anything You know.