Hello Drew,
I have a few suggestions for you.
Rather than only think of how to practice this one bar, my piano professor would encourage you to look at some etudes and exercises. I believe you should look to Buonamici and Busoni for etudes and exercises, as well as focusing on this one bar. Buonamici and Busoni can be easily found on Amazon.com and other places. I, myself am trying to learn this piece. I'm having a great deal of fun with it. Czerny's (G. Schirmer) velocity exercises will help with pinky flexibility, no matter how small your pinky. Liszt/Busoni's Complete Etudes will definitely help (printed by Dover Publications).
I also listen to recordings of the piece. If you use one of the Notation programs, like Finale or Sibelius, you can write the bar in and hear it played correctly. I do this all the time. It helps me to put things in the correct rhythm.
Hope this helps,
Clinton