SmartDashBoard unused objects

[cpapplefamily]

I have taken on the role mentoring two new programmers on the team in what is my first year with FRC. I'm learning too the system and tools available. What I have noticed is when I have the two different programmers who are on different laptops with similar but different code test (i.e. caps vs lowercase, underscores, or miss spellings) that when the next coder downloads their code into the robot and we observe the Smartdashboard we see many of the others items they sent to their Smartdashboard. I have been reading may threads on how the Robot and Smartdashboard shares data through Network tables and have either read past or missed how to clear the table. I'm assuming the "Key Name" is not found so a new "key" is created. I tried powering down the robot and clicking new on the Smartdashboard but will little luck. We have found at times with undocumented sequence of events the Smartdashboard does clear unused items. How do I clear the Smartdashboard keys of unused items?