If plunging doesn't resolve the clog, you can try using a toilet auger or snake, which is a longer tool designed to reach deeper into the drain and break up stubborn clogs. Insert the auger into the toilet bowl and rotate the handle to work through the clog. If this doesn't work or the clog is particularly stubborn, it's advisable to avoid using harsh chemicals, as they can damage the plumbing system. Instead, consider seeking professional help to avoid causing further damage to the toilet or pipes.