As many have before me, I am starting to tackle this topic by having the Bat memorize religious material. It is difficult for the Bat, though, to focus on something so abstract as the spoken word, a reality that I am told is common to young boys. This creates yet another area in which ASL can serve us as a useful tool. Things that are memorized may be memorized with both the voice and the hands.
I've started Ezra with memorizing The Shema, one of the most common of Jewish prayers/statements, in Hebrew and English. As a memorization aide, I've found the following translation into ASL:
Now, if only I could find an equally beautiful translation of the rest of the prayer!