you could use buttons, sticks, pieces of wood, bottle caps or can tabs as long as your hole is smaller that what you use. you may notice that my string is much shorter than the one in the original site. my son was able to pull the string over the top and get the thing off that way. even with the strings so short as i made them, one missionary got his off that way. ok, so there is more than one way to solve a problem. here's a basic on how i crocheted the buttons together. just a tiny hook and pull the yarn through the holes. i did 20 stitches between the buttons and it turned out about right.
i let the boys struggle with these and listened to the conversations. when someone thought they had it figured out, they would hide it under the table so no one else could see. one young man got the buttons off but wasn't sure if he got it right and wanted to know how i had done it. i showed him because he asked.
the object of the lesson is a bit more than the thought on the original site. i told them that everyone is handed problems in life, everyone has struggles. we have to do all we can to solve them. we also know that it is possible, no matter how impossible it seems, God always provides a way. then i pointed out that most of them had not asked for help. i pointed out that we have to help each other in our troubles. we all laughed about the helping each other in times of trouble because they had been really secret about their discoveries. they had a little ah-ha moment about the way they had been teasing each other and telling each other not to cheat. it was all fun and very light. we all laughed about the lesson compared to the behavior. i don't think ah-ha moments need to be serious all the time.
i truly just kind of went with the spirit on this lesson, i had a basic idea and just went with whatever came out of it.