Read through the first page of replies and wanted to weigh in. Are you just talking about for coyote hunting? I wouldn't really bother with it if just for that. As stated, you are never going to beat a dog's nose. You have to play the wind, end of story. No scent control regimen will ever change that. If the coyote gets your wind, it's game over.
My take on this for whitetails is different. I've been running an Ozonics since they came out and have been putting my clothes in a ScentCrusher bag for about 5-6 years now. I think these products do give you a slight edge. Nothing will ever make you scent free. If a deer is down wind of you, it will smell you regardless of what scent control options you use. I know for a fact that the Ozonics has saved me a few times in a tree stand (works great in blinds but I agree is questionable in a stand). I've had deer clearly get my scent, but their reaction to it was different. It's almost like they think what they smell is further away than it really is, not as threatening as a nose full they might get without using it. Anyone who has deer hunted has been winded before. Some of those old does will really get under your skin with their persistence when they sense danger. If you can stay still, I've had them go back to feeding or just walk away when using the Ozonics. Without it they stomp their feet and continuously blow/snort at you pretty much ruining your hunt. Those that think an Ozonics is supposed to be set up so you can hunt any wind is dead wrong. The thing with deer hunting is more times than not, what comes in upwind will eventually get down wind of you at some point. There's also the question of "how many deer didn't you see before using the Ozonics?" I know it sounds a lot like a used car salesman pitch, but it's a question that you can't answer. A mature buck winding you will be gone before you ever knew it was there. Just something to think about. I'm serious enough about it that I'm willing to pay for it just for the little bit of an advantage it gives me. It's definitely not for everyone, but I have to respond when I hear anyone say they don't work at all.
Yes, the Scent crusher bag leaves an ozone smell on your clothes for a bit. Again, I don't personally feel like it's overly alarming to a deer when compared to just a nose full of my human scent. It's simple to just put my clothes in the scent bag each night rather than putting them through a wash cycle every once in a while. Yes, the ozone can break down some of your gear. I've had some elastic waist bands ruined by it. I definitely won't put my safety harness in the bag. Yes, the ozone from an Ozonics can lead to nausea and/or headaches if you don't vent your blind. I leave a window open and don't have issues. Stand or blind, if you're sitting there continuously breathing in the ozone then you don't have it set up correctly. I did just buy a Wildlife Innovation Zero Trace to try out. This is a similar product but doesn't use ozone for scent elimination.
Sorry for rambling. Just wanted to share my experience with it.