boot – Booting from USB MacBook pro late 2009

So I dug up my old MacBook Pro, It previously had El Capitan running on it.

The el Capitan was kind of getting slow, so I opted for making a factory reset(Erase mackintosh HD).

Now I am trying to boot from a USB flash drive that I created in TransMac, however when I use the alt boot, it doesn’t show up in the bootable drives. It does however show up in the Disk Utility when I boot with CMD + R.

Tried clearing PRAM,NVRAM,SMC.

Why in god’s name should such a straightforward task take me 5+ hours to unsuccessfully troubleshoot, whereas it takes me 3 minutes on a regular windows PC to setup.

Anyway, suggestions are more than helpful.

Edit: I also tried the reinstall OS X option from the CMD + R menu, although I get stuck there since apparently my appleid has not been tied with the el Capitan that was previously on the system.