I found Boric Acid to be awesome.. I had used normal baits and was seriously disappointed. I heard about using Boric Acid in baits and was curious so I used it on an Ant problem I had. I don’t like having to re-apply poison, and prefer not to use it at all. There is a Boric Acid Gel if you want the easy to apply, no mix etc method. I don’t know much about Fipronil.
I think that the ultrasonic devices sort of work. I think they work kind of like a very loud noise to a human. The human would normally avoid the area unless they know that something they desired is within the noisy area. It not absolute in its behavior, and doesn’t work if the insect has created something like a scent trail.
I understand what you mean by having to rely on neighbors to be clean with respect to roaches (and ants) and condos. It can even apply to free-standing houses w/ hoarders(super pack rats). I have also seen how ants get ‘moved’ by someone hiring an exterminator for their place and all of their ants end up trying to invade nearby houses looking for water (many of the poisons used by professional exterminators seem to make the ants thirsty) and food.
NOTE: I was in a roommate situation going through college and someone brought an old cockroach infested refrigerator into the house. What a nightmare. It would have been nice to know then, what I know now. – FYI: If you have an infested fridge or furniture – toss it. They get into everything.
