This is the same lesson I learned a few months back. I tried unclogging a blocked drainage pipe too but all my efforts and about a cup of soda and vinegar went into vain so my husband and I finally clogged a plumber and he was done fixing the blockage in less than 20 minutes too. So then I learned if I am not interested in becoming a pro at something, I should stop wasting my time and effort fixing an issue and resort to a pro. Honestly this one decision has helped me save a lot of time, effort, patience and money. Thank you for reminding me of this lesson :)