The answer is quite simple actually. $. In other words Badatz - the most accepted Hechsher in Israel, admitted that they give out Hechserim for Pesach to all types of cleaning products, even when there is no halchic need for one.
"It comes from the public" says, Harav Avraham Joseph who is in charge of "Products that are inedible" in the Badatz. "The factories hear the demand" of the public and ask us to give a Hechsher. Bleach of example, is a product which is inedible and poisonus, and to begin with has no fear of being Hametz. It really "Doesn't need a Hechsher", explaind Joseph, "That is also how we answer people who ask us directly."...
The Rav from the Badatz sees nothing wrong with unnecessary and expensive supervision of the Badatz "Ultimately the Badatz has a purpose - to serve the public. If there is a public demand, we are here to give the public the service that it needs and is interested in."
It would be one thing if I thought that this was a case of making money on halachic ignorance. However I strongly believe that the Haredi public knows better. These are very basic Halachot, that most educated Jews if asked should be able to answer. What we have isn't a case of Halachic ignorance, but rather a case where social pressure is forcing people to buy a Hechsher they know is nothing but a worthless stamp. This already poor public, spends even more money just on appearances. Everyone knows Bleach does not need a Kosher stamp - but god forbid my neighbor will see that I dare to have a bleach without a Hechser!