Janitors: Strike of the Sweepers (Book #4) by Tyler Whitesides
"The stakes have never been higher, and you've never seen squeegees do this before! It is a wild and slightly unsanitary ride as Spencer, Daisy, and the Rebel Janitors find themselves chased by Mr. Clean's new and terrifying half-breed Toxites--the Sweepers. Time is short. With the fabled Manualis Custodem in hand, Spencer must figure out how to summon the Founding Witches if they ever hope to mop up and save education."
Rating: PG+ (It's clean-no profanity or "intimacy." However, at least two characters die, and those deaths are a little graphic. There's lots of Toxite-fighting as well.)
Recommendation: 3rd grade and up
Disclosure: I did receive a free copy of this book in exchange for my honest review.