I think your wasting your time pulling the injectors, pencil injectors cant be cleaned or rebuilt without proper equipment.
And No, a Harbor freight Ulta Sonic cleaner is not the proper equipment!
The failure rate of these style injectors is very very low!
and to have them all fail at once, billion to one odds!
You will also have to replace the 2 seals on each injector, and here is hoping you don't get a seal stuck in the head, because if you do it will take an act of congress to get it out!
What are you spraying penetrating oil on?
There is no threads to penetrate oil into!
To remove, remove the keeper bolt (#20) and plate and use a little force pulling on the center of the injector, or last resort like with a small pry bar under the injector (If you dent or bend them they are junk and they are about $105 each to replace).
Once you get them out you need to make sure both seals came out with the injector (#170, #180).