Wonderful idea! Adrienne, I am not sure if this would work with elastic but I use a bit of PVA glue on the end of crochet cotton and roll it between my fingers then let it dry. It forms a slightly hardened bit at the end and is easier to thread through a hole. I know it is a bit of work to do before hand but it may just work on the hat elastic? Hope it does.....
Every Monday morning we have a volunteer to comes and she shows how to make Jewellery we let them choose colours, shapes, beads and make bracelets, necklaces and the residents do have a great time!.
Making stretch bangles using hat elastic works well also, although it can sometimes be difficult to thread the beads unless they have large holes. Our residents love them for holding their hankies. If made well these last a long time. If anyone has an easy way for threading the elastic please let me know as I usually do the threading but have the resident hand me the beads. I will try your necklaces next. Thanks for the great ideas.