A clogged drain is a common problem which all of us have to face sooner or later. In such a case, you can either stick to home remedies or hire a professional which naturally will burn a hole in your pocket. Sometimes getting the commercial drain products just don't work. Trust me, we have tried several products which we bought off the rack from supermarkets but to no avail. 

Here is my MIL's home remedy for clogged drain:

Pour one cup of baking soda down the drain.Allow the drain to set for 10 minutes than flush it with boiling water and voila' the clogged drain is cleared!

For serious clogging you can add a combination of baking soda and vinegar (cheap one will do), 01 cup of each. Leave this for an hour before flushing down boiled water.
If your have tried these home solutions and the clog remains I guess it's time to call a plumber!