Well, you can't delete your voice BUT you can HIDE your voice.
You see, you have to have your voice for the HARMONY VOICES to be created by the Keyboard and thus be heard.
Here is a song in which you can see that it can be done.
https://www.youtube.com/watch?v=Nj0flwoE2lQYou just adjust your voice DOWN so that it is lower than the BACKUP harmony voices. It took me a bit of time to find the perfect settings for my mic and voice to balance out.
For this song I had to set up 3 different mic settings and save them into a registration. You can watch the video and see me changing out the voices as I press the registration buttons on the keyboard.
1- a setting for my voice alone with just reverb
2- a setting with my voice and the backup singer a bit lower in volume so my voice is a bit louder than the back up singers.
3- a setting with my voice just a bit softer but still mixed in with the backup singers (this is the setting you are looking for).
Regards
Drake