What happens if i pour hydrogen peroxide and Chlorine down the bath tub drain?

Hydrogen peroxide do not harm any body .All hair dye have to mix with hydrogen peroxide which came together when you buy (check) , I use to clean wounds and also put few drops in ear to clean .recommend by Doctors , so this stuff is good for clean the bath drain , but I would like to suggest better use H2So4 from car battery acid .