elbow-grease

Noun

elbow grease (uncountable)

1. (idiomatic) Effort or hard work, especially physical work involving repeated motion of the forearm, such as scrubbing.
   • It is astonishing what miserable saws are sometimes used by mechanics, or those claiming to be such. The only way they can be coaxed or driven through the wood is by having an enormous set, a liberal use of oil, and another lubricator called elbow-grease.1864, Henry Wells Holly, chapter 3, in The Art of Saw-Filing, page 12

   Synonyms:

   elbow juice