We've just begun demanding a security deposit from "high risk" guests (large groups of under 30, no history, no profile). I first explain why they're high risk, and why we must require a security deposit of €xxx ( differs depending on our overall risk assessment), and if they agree to those terms, we will happily approve their booking.
About half the time, it scares them away, which is ok. I'm not inclined to accept high risk guests without a security deposit.
The other half agree, and as soon as they book, I "request money" in the amount of the agreed deposit through the Airbnb system. Airbnb collects it and sends it to us without commissions. I was, a bit surprised, but no problems so far.
When all is well at checkout time, the security deposit is given back to them in cash before departure (they must sign a receipt, of course).
With the extremely high volume of high risk inquiries this year, I'm loathed to continue to decline one after another. And besides, Airbnb doesn't look fondly on that.
So far, it's worked very well. No damages. And we have a real security deposit, just in case.