THIS WORKS (If you have Windows installed as well on a different drive):
In OSX:
1. Use EFI Mounter (download from Tonymacx86 downloads section) utility to open EFI and go to the BOOT folder.
2. Rename BOOT folder to LAUNCHER
3. Reboot to Windows
In Windows:
1. Download and use EasyUEFI utility to delete any extra boot options.
2. Use EasyUEFI to add a new boot entry, select other OS, name it what you want (I just called it El Capitan) so you can identify it when you boot, and click Browse and go through the file directory \EFI\LAUNCHER\BOOTX64.efi
3. Done
Reboot to OSX then restart several times and make sure you aren't getting extra boot options