Aside from the acerbic debate on whether you should Journal your Scratch/Render/Capture disks you should at least stop Spotlight from indexing them. I'll say that having spotlight index your capture drive is debatable but I never have Spotlight index my render/scratch disks. Why? Speed. Spotlight can eat up a few CPU cycles here and there and it can slow down a drive's performance considerably.
Plus, you shouldn't really need to perform a Spotlight search on scratch disks if all you have on them are temp files, render files, etc...
Launch System Preferences from your Dock or hit Command + Shift + A to open your Applications folder (do this while in the Finder), Type "sys" to highlight System Prefs and tap Command + O to open it.
(If you want to avoid the mouse entirely when system prefs is open type "Spotlight" to highlight it then tap Return to open it.)
Click on Privacy and add your scratch disk to the list there and close it. Spotlight will now ignore that disk and you'll never have that hard drive bogged down by Spotlight indexing it for -sometimes- hours.