Use a disposable cup for your "spittoon". Hours of driving while oil pulling will leave you with a really nasty concoction in the cup. You WON'T want to mess with dumping it and washing it out later. If you are just using a paper cup from a fast food place (I stopped on the road at a fast food place for a cup of water and to use their restroom, just to get the paper cup, avoided the food). The paper cup will be OK for a few hours, but if it's not a good waxed one, the oil will start to soak through. Mine was definitely nasty enough to toss by 4 hours. A styrofoam cup would be great, because then you won't have to worry about the oil soaking through.