Yeah. The needle isn't for pushing through the foil to make a hole, it's for making a bump in the foil, and then you sand the bump off to make a hole. There are several advantages to doing it that way, including: i) the size of the hole is easier to control; ii) the hole is nice and round; iii) it has clean edges; iv) the edges of the hole are thin (this is important if you're making a hole in a thicker kind of foil, like for example a piece of beercan).
Originally Posted by NedL
I usually use a knife sharpening stone to grind the bump down, because it's very fine grit, it's flat and it's rigid so it doesn't deform while I'm trying to make a nice precise round hole.