This is one of my favorite functions of WSA.  It is so fast (less than two minutes) that I run it multiple times every day, with no interference.  One of its features is disk cleanup, which is similar to Microsoft Windows disk cleanup, but this works faster.  I wish this function had a disk defrag feature as well (I know I keep harping on this, but I really think it would be worthwhile and really wouldn't constitute bloatware). ;)