Phil, I am wondering if you have the ability to change your instant book settings to have the results you desire. When you go to your "Booking" tab under your listing (through the Calendar and More option), do you have the option to select:
"No one. Guests who meet Airbnb’s requirements must wait for your response."
If so, that would be like turning off instant book - guests who otherwise meet Airbnb requirements would have to wait for you to respond "pre-approve" or "decline".
If you do not have that option (I am not sure what people are talking about turning off/on instant book), then the next best option would be to choose:
Guests who meet Airbnb’s requirements, and also have:Provided a government-issued ID
Recommendation from other hosts
With this option, and both checkboxes checked, the only people who could instant book are those who submit a photo id and also have recommendations from previous hosts. That would be a pretty small group, so most of your bookings would proceed like non-instant bookings.
With instant booking, you have the ability to decline up to three reservations a year that make you uncomfortable without penalty, so if one of those guests had awful reviews or something, you could use one of your three free cancels.
Hope this is helpful information.