I prefer being careful about dumping stuff down the drain, but that isnt always possible.
Zip-It is a thin strip of flexible plastic with barbs on either edge. When pushed down a clogged drain and pulled back out, the Zip-It pulls the clog out, too. You cant beat the price at $1.99. Information: www.zipitclean.com. Available at Lowes, Wal-Mart and other places.