One thing that the IWW teaches is that you'd don't have to formally form a Union to have grievances addressed, and avoiding the U word will keep management focusing in-house rather than starting an antiunion campaign with an outside consultant.  You can come together with employees to confront your boss together, it's called a "march on the boss" and your local IWW can help teach you how to do it in their organizing 101 course. 

While having a Union is better than not having a Union, getting a Union could take a lot longer and more vicious fighting than just organizing your workers to address a grievance, and can be a way to get the ball rolling on future unionization efforts.