How is cleaning fee collected?

According to:


the only way to add cleaning fee is to contact booking.com .

Before I go this way, I want to understand: How is the cleaning fee collected? Is it paid by the customer to booking.com as the regular room charge, and passed (-15% commission?) to the host?

Or should it be collected by the host on site?


I believe you have to collect it yourself as you would do for the damage deposit.

I never set up the cleaning fee as you cannot seem to make it optional!