We had quite a few false bookings or bookings that were "iffy". It is always so frustrating to have these bookings occupying your availability and preventing genuine bookings.
We have curtailed the problem to a large extent by giving only 24 hours to pay the deposit or we cancel it as quickly as B.C will process the cancellation. After the 24 hours we also cancel it immediately on Nightsbridge so that those days become available on other channels even before B.C have cancelled it.
So as soon as we receive a booking we send a template based response via B.C AND we phone or send a text message to notify the booker that a deposit is required within 24 hours and they should see the mail from B.C for details. Obviously the bookings where credit card details have been provided we send a different message advising that the deposit will be processed through their card.
You want to look at your calendar and see only confirmed bookings for at least 2 weeks ahead - be a bit mercenary in weeding out the unconfirmed ones.