Where do NX offers store cookies?

I'm doing NX offers on my Firefox browser, but I want to multi-task and do offers on my other browsers Explorer and Chrome so I can rake massive NX. Do the NX offers store cookies in the same place? E.g. temporary internet folder. I fear multi-tasking will prevent the offers from crediting.

You know they can catch people doing that and totaly ban them from taking anymore surveys.

Please tell me where it says on the site that I can't do that, especially if I fill in valid information. Otherwise, post ignored.