Summarize:

All you'll need is a small disposable glass jar and a tube of clear silicone craft glue. This type of glue stays relatively flexible, no matter how dry it gets. Other types of glue will not work for this method. Leave the glue to set. This should take about 24 hours. Once it has congealed, it should look similar to dried wax. To double-check, touch the glue first. If it's still sticky, wait a while longer.
Gather your materials. Let the glue dry.