Mememe wrote:in an emergency I have used an ordinary pen wrapped in selotape (scotch tape) to the desired thickness
I also used to do this, but if you don't get the size right (if you make it a little too big) it can really be frustrating with the tape all messed up inside the lock.
What I did was go to a local hardwarestore and buy a round wooden stick (dowel) - they have all the sizes you need and if you just buy 1m. you have enough for a lifetime of plug followers. Just cut pieces off it.