Congratulations to your Dad and his admirable routine.
Lots of people combine their Iodine with juices and/or antioxidants and do very well. They all get mixed in the bloodstream anyway so the notion of a necessary separation is a theory without foundation.
So glad to hear about the brown urine. In reading some Iodine reports from the 1800s, the doctors said patients experienced what we would call "detox" in bursts.
This has happened to me. I'm going along fine for months and then it feels like a bunch of bromide bursts out. Bromide retardants are deep in our fat and may take years to get out.