Have you tried powering your device down and then turning it back on?

There is a gtk icon cache that doesn't get cleared properly (I think it's a filed bug) and if you do a df -h before and after installing an app that installs nothing to / you'll see space go down over and over with each app. Once you reboot or power down (I suggest powering down due to the seventeen reboots brick bug) the cache is typically cleared next startup and your rootdir (/) space should go back to normal (somewhere near 50mb)