It takes effort to make something "squeaky" clean. When something is that clean, there is no trace of dirt. It is as if the surface was as new again. When we ask God to clean our hearts are we asking for "squeaky " clean ? Or are we asking for a clean that looks good from a distance?
Have mercy upon me, O God,
According to Your lovingkindness;
According to the multitude of Your tender mercies, Blot out my transgressions. Wash me thoroughly from my iniquity,
And cleanse me from my sin.
Psalm 51:1-2