Aha! Maybe some twine? Wire?
I didn't think that something mysterious and sticky called 'Sexauer' would be of any help--but my inner 13-year-old boy did find it amusing. The search continued. In any lab that's been around for a while, even the most immaculate of them tend to accumulate a lot of junk. I struck gold with this drawer:
Heavy gauge unplied copper wire? Dear diary--jackpot. Copper is very ductile: you can often bend it with no equipment other than your hands.
I started with a straight piece:
Bent it in half, one side a bit longer than the other, then curled the longer side into a loop:
Readjusted by original bend so that I could easily move the unbent side in and out of the loop, but with a little poking through so the stitches would be trapped.
I also filed the ends a bit, just to make sure they wouldn't snag. Here it is in action:
I was feeling quite pleased with myself, but not really seeing any advantage to this as opposed to just a strand of yarn. Then I made an error (naturally) and had to pull the work back out to before where I used the stitch holder--bingo. It was so much easier to get the stitches on and off using a rigid holder, rather than yarn. They slid off like buttah. It's cliche, but necessity is the mother of invention.