scrub off
To clean away some substance or residue (from something) very thoroughly and vigorously. A noun or pronoun is used between "scrub" and "off." You should be scrubbing off all the caked-on dirt and grime from your bicycle at least once a week, or it will wear out a lot faster than it would otherwise. The salt-and-sugar rub helps you scrub dirt and dead skin cells off your body, giving your skin a bright, healthy glow.
scrub someone or something off
to clean someone or something by rubbing. Mother scrubbed Timmy off. Liz scrubbed off the countertop.
scrub something off (of) something
and scrub something offto clean something off something by scrubbing. (Of is usually retained before pronouns.) I have to scrub the mud off the porch steps. Did you scrub off all the grease?