I echo Wombat's comments on this page.
Go out and pay an instructor to teach you to do this stuff in a proper approved aerobatics machine.
More experienced pilots than you all have died doing this stuff.
I can't believe people are posting techniques on here - and reading it, it's obvious that these guys don't know what the hell they are talking about.
Think about what you write, or you'll be reading about another pilot and his pax in the papers....