I've never used one myself, but every report i've read says the same thing. They work for a couple of weeks, but won't get you through flowering without odour leaks.
They take care of most of the smell. I can smell flowers in the room that my box is in. They help, but I wouldn't count on them for 100% Security. I like them for light traps / intake filtering.
Haven't heard of it but ozium was the first I heard of a product which plugs the scent receptors in the nose. I've heard a few different ones by now but they've all been just unique shapes and such.