The right way to clear out the obstacle on costmap?

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Hi all

I confronted a problem. In my application, I need to reset the pose of the robot now and then (by publish to the /initialpose for amcl), however, after I have reset the robot pose, the previous obstacles around the robot are still there on the costmap (global costmap and/or local?) which always resulted in no valid path found by the navfn global planner. I am asking what is the right way to clear out the obstacles on the costmap after I reset the pose of the robot? I am now using fuete.

Thank you everyone!