Paul you are absolutely correct - the schools often have a 30-day probationary period. This is their 'Demo'. In fact, having someone do a single first-time class at a new location isn't going to tell the story anyways.

They can train a little or give advice, let the teachers get comfortable, give them a few classes and they can let a person go if they can't adjust.

So there is no practical or meaningful reason for the 'Demo' and besides this what interviews and resumes are for anyways in terms of getting an idea of personality, presentation etc.

I can't actually name a single school doing this because this season its EVERY SCHOOL. Its being done as if a standard granted right they have to get a free rotation of pre-sign up classes.

Now.. my advice might be this. IF asked to do a "Demo" under the promise they are very interested in hiring? Then agree to doing a paid class. 200rmb maybe. IF THEY HIRE YOU then say you will wave the fee.

Watch how almost every single one of them will refuse the agreement!! It means they were not going to hire you anyways. (if they were they'd accept the low low risk offer).