Completely clean (7)
(Other definitions for immaculate that I've seen before include "Perfect" , "Spotless" , "Dogma that the unborn Virgin Mary was preserved from all original sin" , "Faultless" , "Free from flaws" .)
(Other definitions for squeaky that I've seen before include "- Clean means virtuous" , "In need of some oil" , "High-pitched" , "Sounding like a mouse; completely (clean)" , "Above reproach" .)