With 40 years in the plumbing and drain cleaning business we cannot, to this day, believe people are still trying to use a liquid drain cleaner to open a stopped up drain.
Please Stop! Unless it is a small amount of hair in the trap or a small buildup in the trap or pipe running to the main drain this will NOT work! No matter how hard you try to prevent stuff from going down drains, the grease, soap, tooth paste, hair, etc. is going to build up and eventually cause a stoppage.
Liquid drain cleaners we admit are a very good “preventative” measure from this happening, but once it totally stops up you are truly pouring your money “Down the Drain”. Take that money and put it towards the cost of a plumber coming to your house and opening it correctly. If you are really enthusiastic then you can rent a drain machine and do it yourself. Of course this entails driving to pick it up, using it correctly and not causing damage to your plumbing system or equipment you rented, which can occur at times and then returning the equipment.
Even the best plumbers with years of experience can run into difficult drains to open and damage their drain equipment. Save your time and money and call a licensed plumber. You will be glad you did.