Currently if a potential guest attempts to book and you accept and he has no funds then he has 24 hours to pay - (often resulting in no payment and a lapsed booking)
If that request is for an arrival in the next 24 hours the dud booking blocks other guests from booking
This Easter week end I lost $350 for Sunday and Monday nights because of this - NO help from Airbnb help - just words and lack of understanding about bookings system
{suggestions like "Dont allow last minute bookings!! - yes really)