Well, even if we do indeed delete the web browsing history and cookies and passwords they can always contact the internet provider to ask for a list of your history of visited pages.
That's why i'm trying to devise a way to make it perfectly clear to them that i commited suicide with a certain method, that i learned somewhere, without drawing them to the internet. I have to come up with a theory of where i learned about my method without it being on the internet.... I can always say that i read it in a newspaper online though.....
The reason for this is that i want to make the police sure that i ctb by myself to exclude any "crime theory" regarding my demise, but there is always the question of where and how did i learned and purchased the equipment for my method, which will lead them to the internet and i don't want that. My suicide note will have to be very well written.
Although i realise i may be overthinking all of this: the police in my country are much less sophisticated and they lack resources when compared with other european countries, so they will probably take my note to it's every word (wishfull thinking).