I did indeed give myself a blister practicing glissandos yesterday. It's a small one because I stopped sooner rather than later. But it's still a small spot of hurt so I didn't play today.  

Instead, I listened to approximately 1:42:26 of Prelude 5 in order to determine what's useable. As usual, on the first listen, nothing sounded great to me.  Oh, and I never want to hear it again.