To waste effort on a futile project.
waste breath
To speak in a manner which is needless or futile; in discussion or arg…
like talking to a wall
A futile or unsuccessful attempt at communication due to the ignorance…
plow the sands
to spend considerable time and effort to do something useless; to wast…
piss money up the wall
To waste money, normally through ineptness in business.
rock the boat
To disturb the status quo or go against rules or conventions, as in an…
hit a wall
To come up against an insurmountable problem.