According to Philter, the Pocket is loaded with some futuristic-sounding tech. There's a "kinetic energy multiplier" for starters, along with a "phase transition chamber." All you need to know, though, is that you take a drag on your vape/cigarette as you normally would, exhale through the Pocket and voila, no eye-watering clouds or wretched cigarette smoke. If you're a considerate nicotine user (and you should be), this might be a handy addition to your everyday carry.
Having an accessory for your vape might seem like a recipe for forgetting it or a burden (double fisting as you walk). To combat this, Philter also makes something called the "Phlip." The Phlip appears to be a case that fits popular, smaller e-cigarettes (like Juul, or gas station disposables) on one side, and a Pocket on the other. The idea being that you inhale from one end, "flip" it, and exhale into the other. Phlip costs $30 and also includes a Pocket.
The first thing to consider is the longevity of the Pocket. Philter claims it's good for about 200 exhales. This means if you hit your vape around 10 times every time you reach for it, and, say, use it 10 times a day, the Pocket will only last two days. Of course, you likely won't need it every single time you're smoking or vaping, only the times when you might annoy other people -- so it'll depend on your usage. Handily, Philter offers a subscription service which will ship three Pockets every three months, for $30 (a saving of $15 over purchasing individually).
The second thing to consider -- if you're using this with tobacco cigarettes -- is that this likely doesn't counteract all the negative effects of secondhand smoke, so it's not a solution for keeping family members in the clear. Not least because you'll still have the secondary smoke runoff from the lit cigarette itself. Philter said in a statement: "While our proprietary technology is exceeding initial expectations during internal testing, our products are now undergoing controlled performance evaluation testing with an independent accredited laboratory." In other words, once those tests are in, we'll have a better idea.
So, is this a practical way around the social stigma of vaping and smoking? I imagine it might help, even if it does feel a little goofy. Just don't get any ideas about using this as a way to vape in places you normally cannot.