My Dear Husband just helped me with my thumbpicks, which are now too small to go over my thumb plus the corn pad.   He put a small piece of wood in the "jaw", then put the pick plus the wood in a bowl of water. Another bowl of water on top of that kept the thing submerged, so it didn't overheat. After 55 seconds in a 700-watt microwave on High, the pick is looser, but not too loose. The piece of wood is about 1/4 inch thick.

Turns out the instrument I've been playing is one somebody gave me a couple years ago. My own was in its case in an upstairs closet, safe from the dust of a home renovation. I wondered where the stickers had gone that show me where the chords are for D-A-G.

Flow gently sweet Afton - 2 diff. melodies
Finiculi, finicula
As we marched down to Fenario
'Tis pretty to be in Ballinderry
All my trials
O du froehliche