We've got a small amount of cloth-covered wire in our place (needless to say, I'm gradually replacing it!) which is joined using some kind of combination of those two. The wires are twisted together and covered in cloth tape, but are also filled with some kind of "rubbery goop" (which is actually quite tacky these days, but I suspect was a lot firmer when it was originally done).
Nasty horrible way of doing it, anyway. The old cloth-covered wire's a nightmare too - after 60-odd years the internal insulation like to turn to dust if you so much as sneeze near it.
cheers
Jules