Though it may not be the most appealing way to unclog a drain, manually removing the problem is a sure way to fix it. This method is best used when hair is the likely culprit, such as for bathtub drains. Most hardware stores stock an inexpensive tool called the Zip-It. A long, thin plastic tool with backward-facing teeth, the Zip-It is inserted down the clogged drain. On the way out, hair and soap scum get snagged on the teeth and are removed from the drain. Repeating this procedure several times usually clears the clog.
To prevent hair clogs in your tub remember to clean out any hair that has accumulated on the drain cover after each bath or shower. Always throw hair in the garbage instead of rinsing it down a drain.