I just want you to know that I also got some serious brain fog while I was in my "MMS cleanse" stage. I think I was up to 8 drops once per day when it started. It lasted for about a month and did get me worried. One day I was having a phone conversation with someone to whom it was important that I appear alert and normal. She asked me for my phone number and for the life of me I could not remember it! Embarrassing.
I did not have lyme disease. Once I pulled out of the brain fog, I would say that my thinking became sharper than it had been in several years. My personal belief is that the Miracle-Mineral-Supplement worked on something that was impeding my ability to think clearly, making it worse in the short term but better in the long term.
I have heard of others experiencing brain fog as well. I hope this helps.