I am not sure what a "safe edge file" is?, If you want to remove the teeth to make a clean edge on one side of a file, a power sander of some kind with ceramic belts or paper would be best, Silicon carbide in second place and Aluminum Oxide if you don't have anything else.
It can be done on just sand paper or even the side of a curb if you have enough elbow grease.
Welcome to KD's and have fun with your file project.