Today when I booted my arch laptop from a usb I noticed that I have several old bootloader entries that I don't need anymore. They don't seem to be hurting anything, but it annoys me that they're there. This is how I removed them.
This gives you a list of all of your entries. You'll have a list of entries...each starting with something like
Boot0019 followed by the name of the entry. Identify the ones you want to remove and remove them with...
efibootmgr -b 0019 -B