No professional needed.
With all puns possibly intended, most folks know the sinking feeling of a clogged drain. These inconveniences typically come at the worst time, when the sink is full of food, toothpaste or worse items ...
Pour 1 cup of baking soda into the drain, followed by 1 cup of vinegar. Let it fizz for 15 minutes, then flush with hot water. Boiling water works wonders. If the clog persists, carefully pour boiling ...