Absolutely needed? No. Unless you got the one that MONGO did on his last day on the job. There are ones out there that have been put on by a gorilla, cross threaded and won't come off unless you cut them into pieces, but they are rare in our shop. Not saying it doesn't happen, but it is not an "everyday" happening followed by "Jesus, again?!"
Does it make the job easier? Yes, it will, but it is not on the "necessary" list for the "average" person doing this operation.
A wet, high thread count piece of material, doubled over a few times, will provide AMPLE application of force when torqued in a normal bench vise for you to work against WITHOUT damaging your components.
Good luck and take some pictures of your set up for the rest of the members if you can please. It's always helpful.