To answer this correctly I can't say 100%, but in a Shonen Jump interview from when the manga first debuted over in th US the very same question is asked and Tite Kubo responds with "Bleach" being the title of a song By Nirvana perhaps, though I'm not entirely sure my memories gone a bit fuzzy on the topic. i Offer this tidbit not as an absolute, but as an answer to give piece of mind to Kreachure, who really shouldn't worry for this is why Vandal Buster ONyx is ON the case.