Am I totally imagining it, or was the fact that one of the London Bridge terrorists

[Burney]

They used to put that juice on the pipe and heat it up and it smelled nice. What was that stuff called?

Maybe it was gas fitters actually. Same thing, I suppose.

I once had a chap spend most of a day in my loft trying to work out how my pipes worked. He was getting awfully cross about something or other.