I don't know about your area, but here in Utah, essential oils and herbal remedies are very popular despite not having any scientific evidence whatsoever.
People buy whatever you tell them to buy, provided you give them an emotional reason to buy it. We just had someone try to sell to us in our home today, and when we told them the price was completely unreasonable, they tried to appeal to emotion (we need this sale to get a bonus, so we're willing to give you an awesome price...).
If you're a good enough salesman, you can sell air, as long as they think there's something different about your air.