Nope, you don't need the esata, or the dongle.
Here is a tutorial, "
You can also follow this guide if you don't have the limited edition, that comes with the eSata station. If you are using just the flasher, you will not have anywhere to plug in your hard drive.
But don't worry. When the guide says boot to XMB, just boot to the "cannot find hard drive" screen. Before you do Chapter 2, Part 1, Step 13, uninstall your flasher, replace thermal compound, rebuild your PS3, and then continue with the guide.
"Esata"
ps3hax.net/showthread.php?t = 33989 = not sure if im allowed to link but there

just find the bit where it says chapter 2 part 1 no fsm downgrade
Credits to :playerkp420 For making it,
Thanks,
Teddy