I had my last truck for 12 years and did about six full flushes with the Brembos, I gave up after the second try, I would drive for a week or so and then had spongy brakes. I also bought the reverse ******** thing, that does not work either. So for peace of mind I just paid $115 for fluid and bleeding.
Sometimes they can be a bitch!!! Air rises and gets stuck in places... Some take time and even try to generate some heat in the fluid then get back and bleed again...