I have stayed in many BNB's and house exchanges and i can say that this was the most nasty and foul-mouthed host i have ever encountered.

We arrived at her place and were met by a person who spoke no english who then showed me 2 units and asked which was mine? I had no idea host had many units so I pointed to his phone and said phone the host - he did so and they spoke in a foreign language - I asked very politely if i could speak to host? I did so and was met by abusive language telling me to get out, swearing and then hanging up on me. Not a nice way to start - obviously there was a misunderstanding on which unit was mine but there was no reason for such agressive and nasty behaviour.

In her Unit, the host had laminated pages describing financial penalties for various things - among them stains on bedsheets with pictures showing possible stains that would be subject to heavy cleaning fees.
We pulled back the cover on the bed and lo and behold - there were the same stains on our bedsheet! We took pictures and emailed them to the host telling her that we were not responsible!

This was our first negative experience with Airbnb - the laws of probability say that this will happen sooner or later - so we will continue to use Airbnb, but never again with this host.