I don’t like using the harsh chemical product either. I kept seeing this idea on youtube & decided to try it. Put 3 tablespoons of Baking Soda down the drain. Follow that with about 1 cup vinegar. I pour the vinegar kinda slow so to keep it foaming. After the vinegar, wait about 10 minutes & pour some hot water (out of microwave) down the drain. The people of YT claim that will also unstop a drain, but that makes NO sense to me; however, it DOES work well with a slow drain. Since I’ve started doing this, I now only need to do it maybe once a year & my pipes stay running smooth. The first time I tried it, I been shopping in my local dollar store. Their store brand baking soda was 2/$1 & the vinegar was $2/bottle.So, I decided that for $3 that I had nothing to lose & I could clean it more than once IF necessary for the same $3!!! I could tell on the first use that I was going to like it. I don’t think using just plain vinegar would be as effective, but I could be wrong. The vinegar mixing with baking soda creates a foaming action that I’m assuming creates the right action to clean the pipes. Now every Spring when I do my Spring cleaning, I start with 3 TBSP Baking Soda followed by the vinegar in my kitchen sink, my bathroom sink, & the tub drain. I’ve also been known to throw some soda in the toilet followed by vinegar. Makes everything smell a bit better!!!
As an FYI, a quick search says that PVC pipes Melting temperatures range from 100°C (212°F) to 260°C (500°F) depending upon manufacture additives to the PVC. Water boils at 212°F, so technically speaking you could harm your pipes. Using the soda & vinegar method doesn’t keep the hot water in the pipes for long, so any damage should be minimized!!!