A flood dose is a whole different ballgame from low doses. yes, it's a powerful dissociative, but it also affects a great number of receptor systems. During the flood ( a few days long), opiate withdrawals will be blocks, or mostly blocked. They'll come back after that if you didn't get yourself most of the way through withdrawals before you took the flood. But the effect it has, or had for me anyway, was to rearrange my subconscious mind. I came out of it with some light withdrawals, but I simply did not care. The thought of taking an opiate to make myself feel better seemed like absolute insanity. It was like the 10 years of opiate addiction I had just disappeared from my subconscious mind, leaving me to deal with some mildly unpleasant restlessness and anxiety that I just powered through easily.
This effect does not een remotely happen at lower doses. You have to understand 17-20mg/kg and expect to be out for days, and unable to care for yourself. It's super intense and dangerous for the heart, too, and takes a lot of prepaparation, and ABSOLUTELY you must have a sitter for 3 days to make sure you don't do weird shit, for me, I was dreaming whether awake or asleep for 3 days and nights and I had no ability to care for myself, even though I felt like I was fine, at the time. It was really weird.