The two hardest parts of the Genocide path, other than getting a decent time in Snowdin, are the Undyne and Sans fights. It would likely drive a lot of people away if the only chance they had to practice the fights was when they got to said fights, and even then they'd probably be behind the leading splits because of item use.

I'm providing this for common courtesy, though the other save file was found on Reddit since I didn't feel like going through the worst parts of the game to get to Undyne and then just stop there.

I'm not sure where Undertale's files are saved on non-windows platforms, but on Windows it's C:\Users\USERNAME\AppData\Local\UNDERTALE.

The only thing you can't fully replace just by altering appdata files is finishing the Genocide run, so you still have to wait ten minutes between complete runs as a minimum.