Britney Spears' second stint in rehab didn't go much better than her first. ETonline.com is reporting that the Mrs. Clean of pop tarts checked out of Promises residential treatment center in Malibu this morning. (The center's website states that rehab "participants who feel safe, secure, and 'taken care of' always do better in treatment.") It's the second time Britney has checked out after spending less than a single Earth's rotation in the tank. Details are sketchy as to why she left this time; more to follow, whether you like it or not.