The answer to 'how to clean drain cleaning' is to use a combination of baking soda, vinegar, and a plunger to clear clogged drains. First, pour a cup of baking soda down the drain, followed by a cup of white vinegar. Let this sit for 15-20 minutes to allow the chemical reaction to break down the clog. Then, use a plunger to forcefully push and pull the water in the drain, which will help dislodge the clog. Repeat this process a few times until the water drains freely.
If the clog persists, you may need to use a drain snake or auger to physically remove the blockage. For tough clogs or if you're not comfortable doing this yourself, it's best to call a professional plumber to inspect and clear the drain properly.