Drain cleaners are not recommended for unclogging toilets. Using a drain cleaner in a toilet can damage the septic tank as well as the toilet's wax ring since they commonly contain harsh chemicals.
Unclogging a toilet can be a hassle, but it is entirely possible. Since drain cleaners are advised against for unclogging a toilet, using a plunger is the best option. They are common in most households and are fairly inexpensive. Snakes are another option, but it takes a little more effort and know-how to use one correctly.
Using a Plunger
When using a plunger, it is placed in the toilet with the bell shape down. It should be positioned completely over the hole inside in order to create a tight seal. After it is in place, gently push to remove the air. Failure to do this can result in the water being splashed up. After all of the air is forced out, the user should plunge vigorously while keeping a tight seal at all times. Continue plunging until the water drains completely. After the clog is fixed, it is important to let the toilet fill and flush it to ensure it is completely unclogged.
Using a Snake
A snake is a long wire coil that feeds through the pipes until the clog is pushed out. To use a snake, feed it down through the toilet as far as possible and turn it clockwise, then counterclockwise. This will loosen the debris or cause it to wrap around the snake so it can be pulled back up.