Just contacted Amazon about them ... I've received a refund, even though I purchased them prior to February, and they've assured me that they're going to stop selling them until the seller can prove it was a one off.
Son took screwdriver to remove them after the flames had died down to check the flames were in fact out!
Where are the rubber plugs?
If anyone's fancying buying these then please be cautious where you place them, as I stated before, I thought they were great and gave them good reviews on here & Amazon. It went off like a rocket with approx 6" flames literally jetting out of the side like an afterburner on a jet plane, I hate to think what could have happened if we weren't present when it went off!