The LW version of the phrase is the idea that oftentimes a seeming solution fails because it hasn't been tried hard enough; by doing it even harder it becomes effective.
I've usually heard it as "If it helps but doesn't entirely solve the problem, try doing more of it." rather than trying more even if it doesn't seem to be doing anything. (See this Zvi post: https://thezvi.wordpress.com/2017/12/02/more-dakka/ )