I wonder if clever marketing and a shithot screening process could get more short fruitful bookings- I'd love to try but don't especially want the footfall in my apartment block.

I only do it when I'm in hotels for the same reason. I reckon mine go well because I tell them it's only HR and oral. If they want full service they can either pay a half hour or find someone else. What I have found is that enquiries for quickies are the MOST likely to haggle; any hint of that and I just cut them off.