The guest must leave the house in the same condition it was in when they arrived. Therefore, the guest is the one responsible for cleaning the house after the stay.
However, there are some hosts that have a cleaning person in charge of that.
For this reason, it is important to discuss how the cleaning will be handled during the conversation before the exchange has been pre-approved and finalised. It is better to be clear about whether the host has a personal cleaner that will do it or whether the guest will be responsible.
If the host charges a cleaning fee, guests will have to be informed BEFORE the exchange has been pre-approved and finalised through the GuestToGuest platform.