Remove useless entries from messed up grub?

Solution 1:

In your case Grub-Customizer might come in handy.

Install it :

sudo add-apt-repository ppa:danielrichter2007/grub-customizer
sudo apt-get update
sudo apt-get install grub-customizer

Open it, and remove all unwanted entries :

enter image description here

Click on save. done.

_{Personally, I don't prefer these types of automated tools. I will update this answer soon if I find a manual way of doing this.}