Scrub off
Definition 1 of 2
Pro Tip 1/3Physical Action
Scrub off involves physical effort to remove something from a surface. 
I had to scrub off the gum stuck to the table.
Pro Tip 2/3Use Rough Tools
Use a brush or sponge for effective scrubbing. 
To scrub off the grime, use a steel wool pad.
Pro Tip 3/3Intensity Required
The phrase often suggests that simple washing isn't enough. 
I have to scrub off the stains; soap alone won't do.