New product visibility value

[MichalV]

Hi everybody, I added new visibility value "new_visibility" to list of the visibilities in admin product page. Then I wanted to use this value, in home page - new products, category products, and search. 

I changed all SQLs in classes Product, Category, and Search. I changed AND `visibility` IN ("both", "search") to `visibility` AND IN ("new_visibility") for testing purposes. Products does not have this new visibility set. My expectation was that I would not see any product because in all sql queries use visibility with "new_visibility". But Nothing happened I steel see all products. 

My questions is how is possible to change and where sql queries for list of products in home page, category page, and search. My idea is that user set your ZIP code, shop stored it in cookie and shop show only products in home, categories and search by this new filter value when ZIP code is different like  inserted in backoffice. I want to switch condition with visibility depends of zip code from cookie check.

Thanks