You definitely want to use the multiple browser method when applying for multiple cards from the same issuer, regardless of the issuer.
And it's generally considered better to apply for all your credit cards in as short a time period as possible. When I do an app-o-rama, I crank them out as quickly as possible in one sitting. You don't want to a wait a day or two and have the first app's hard pulls show up when the later apps do their pulls. When you do it this way, they're all in the dark about your other contemporaneous apps.
This takes some research to figure out who pulls from where in your state and how to distribute the apps amongst the bureaus, but it's worth it.
As for deleting cookies and such, firefox and google have a private browsing mode that makes this easy to accomplish without futzing with anything else. IE might have a private browsing setting but I don't use it much, actually only for applications... ;-)
Is the three browser method idea only if I am applying for multiple cards from chase or multiple cards at once or from Amex, or I need to this even when I want to apply like for one chase card and one Amex at the same time . And I also would like to know if I am deleting the browser history and cookies is it the same helpful ??