I journal a LOT. T gives me journaling as homework, both on a specific subject that she wants me to get deep into as well as my reaction to the session. If there were things I wanted to say but couldn't I use journaling to say them, usually things to do with attachment/reactions to what she said/did/. I use journaling as my deep thinking tool, for analysis and introspection, sometimes to jump-start a conversation I want to have with T, too.
Disclosures though I use spoken words for.....like abuse, say. I just can't write those words, even though it is hard to say them, too.....