From Proctor & Gamble, it's the PUR water purification packet. Dump the contents into a packet of 10 liters of water, and it kills the bacteria. Wait 25 minutes, pass the water through a filter, and a family has safe drinking water. It costs P&G 3.5 cents to make one packet, and that's what the company sells it for.

For demonstration purposes, the representative dumped soil called DPA Dirt No. 3 into some water and ran it through their process. I tasted the result. It was fine. (P&G uses the PUR brand for water filters too, but the purification techniques are completely different.)