I can't really add to the double or triple plays, but re: the grammar - personally, if I'm proofreading something I would get rid of the comma between the thats. Read it aloud - it makes no sense to pause there. Maybe it's a hangover from German where it's a grammatical necessity to have the comma after 'dass' [how does one do an s-tset??]. It's often fine just to have one 'that', too, but the second that places emphasis [ I think, anyhow]

Alexis