That article sounds very familiar. I feel like I've read exactly the same article quite some time ago even though it appears to be a recently posted one. I looked up a research article based on that news story back then, too.

Anyway, I've never seen this product claim to remove petroleum, specifically.

For the more science-minded, here's something from that research article.

Quote:
Its ingredients include ferric sulfate, bentonite, sodium carbonate, chitosan, polyacrylamide, potassium permanganate, and calcium hypochlorite. Each of the ingredients are commonly used in municipal water treatment plants. The ingredients have been specially formulated in single-use sachets to work quickly on small volumes of water. The water treatment process combines precipitation, coagulation, and flocculation with disinfection. It aggregates and facilitates the removal of suspended organic matter, bacteria, viruses, parasites, and heavy metals in treated water. One single-use packet contained sufficient calcium hypochlorite to leave a residual chlorine concentration of 3.5 mg/liter when added to 10 liters of demineralized water. When added to contaminated surface water, the mean chlorine residual was 1.5 mg/liter.

Am. J. Trop. Med. Hyg., 69(4), 2003, pp. 411–419


You stir it and let stand a few cycles to make sure it reacts with everything, strain out the precipitates through a cloth, and you're good to go.