As a Master Plumber and Expert drain cleaner I try to keep away from useless chemicals and toxic/harmful ways to clear a drain
Here are TWO articles I hope can help you
http://www.masterplumbers.com/plumbing/plumbviews/1999/jetters.html
http://www.masterplumbers.com/plumbing/plumbviews/1999/chemicals.html
The only ones who I know who do use “chemicals” are the misfits who dabble in the trades pushing chemicals on the unsuspecting public to make extra money for their lack of skills.
There are some Boiler chemicals and cooling towers that are used to prevent fouling of drainage and condensate lines.
Most of the chemicals sold over the counter either contain sulfuric acid Or lye and neither one is great for older piping systems or peoples pets or eyes or the environment
Good luck sorry if this doesnt help