A common misconception among many people is that drain cleaning products are the solution to any clogged drain in their home. The truth is, oftentimes they cause more harm and can have very damaging effects. Aside from the harmful effects they can cause when they come into contact with skin or eyes, they are also damaging to your pipes.
As shown in the picture, if the drain cleaning product sits for a period of time, it begins to corrode the metal piping. If these agents are used too frequently or if they do not clear up the clog they just sit in your pipes and eat away at them. Most of these products will corrode plastic piping even quicker.
Having these agents sitting in the pipes becomes especially dangerous when the drain pipe has to be cut in order to remove the clog and the person cutting the pipe is unaware that chemicals have been used. Once they cut into the pipe they are at risk to the harmful effects on their skin and eyes.
When considering using drain cleaning products in a toilet think about how long the chemicals will sit in the toilet bowl. Given enough time, the chemicals in these agents will settle onto the porcelain allowing the concoction to heat up and cause one of two things to happen. First, it has the potential to crack the porcelain bowl; meaning you will now have to replace the whole unit. Second, there is a chance the concoction could explode; damaging the fixture, piping, and surrounding area. Both scenarios will result in higher costs than unclogging the drain properly in the first place.
For reoccurring clogs you should always call for professional help rather than risking the cost of re-piping your home. So the next time you go to pour some drain cleaning product down your drain, consider whether or not it is actually worth doing so.