Right now I'm at 50 mgs for 3 days, and 50 mg off for three days...but I'm going back to 100mg (3 days on/off) as soon as I get some tamarind (to help excrete the fluoride, which I feel is at the core of my detox symptoms right now). The salt takes care of the majority of the known bromine detox for me.
I have dosed (since 2/20) anywhere from 0 drops to 16 drops (96 mg) of Lugol's.
Your theory about the mercury makes mighty good sense to me :) And bile (as you may/may not know) is a major trigger for peristalsis (the squeezing action of the intestines). So keeping a good bile flow (don't forget to ingest plenty of oil), is a great way to keep the colon active.
As far as the 'halogen brain fog' it also makes sense that upping the dose starts a detox where there previously was none (or little).
Since equal amount of iodine/'other halogen' results in the other halogen winning (due to atomic weight), it just makes sense that some of us need to up our dose if we're to dislodge the major stores.
'Sounds to me like you're doing great things (and thinking QUITE clearly :) 'Keep up the good work!