I used to do this on my Galaxy S5, way back in the day. I would use Root Explorer to copy a .ogg file that I converted from a .wav file to the root/system/media/ui folder.
I'm trying to do the same on my G6 after rooting. I have full root. Mag...
Except no disable dual clock option to choose on my lock screen page. Any other ideas? Um, forgot to mention I'm on F600S stock Android N version
Install this app: Dual Clock Remover