I have two cats and a MIL who likes extremely smelly food and strong perfumes. Unfortunately, I have chronic migraines, so these smells affect me keenly on a regular basis. I can't use regular scented air fresheners because they're just as bad for triggering head pain. This spray is essentially a reset button, and it has drastically increased my quality of life.
It works best when sprayed up as high as possible (the mist then passes through the air below), every few feet that the smell exists.
Two things to note: firstly, if the origin of the scent is still active (uncovered food or garbage etc), it will be less effective as the air will commingle and bring the scent back to you. Secondly, this is not 100% completely scentless once sprayed. When I catch the scent early, I do not smell the Zero Odor. But if my hyperosmia has kicked in, there is a faint "cleanser" smell, a bit like chlorine but less invasive. It also fades within 5-10 minutes or less.
Overall, very worth it, I would recommend to anyone with hyperactive senses of smell.