I didn't see any usage stats in the article. But if the English also made their own, then I guess they were widely used. If any one has any more insight, I'd be keen to know more.

Brandy, chocolate and cigarettes. After a rough day I can imagine that’s pretty nice.

I recall a movie about British WW2 pilots downed over German-occupied territory whose escape back to England involves hiding out in one of these--a German one. But now it is bugging me that I can't remember the title.