Putting cleaner Chemicals in Drains in your home can be very harmful to the plumber. Store bought drain cleaners usually only work on small hair clogs. Once you’ve poured them down the drain and it doesn’t work, who do you call? Your local plumber. Please let the plumber know what you have poured down the drain before he goes to work with the sewer machine because backsplash can occur and be harmful to skin, eyes and clothing. Chemical drain cleaners are made of caustic chemicals such as bleach, lye and potassium hydroxide.