Without understanding the root cause of why the immune system became misinformed in the first place, and without knowing whether that cause still exists or has even become worse, you're playing a very dangerous game telling it to forget everything it knows and just blindly hoping it will make better choices the next time around, treating it as if it were just a random outcome and gambling with people's health. Imagine trying to treat someone with arthritis and after treatment their autoimmune situation gets even worse and they become diagnosed with MS, so you treat it the same way again and it becomes a very aggressive form of MS. That violates the hippocratic oath to do no harm, which is why there really isn't much interest in such approaches unless they've been proven reliable and safe in carefully controlled studies, which your proposal hasn't been (and presumably wouldn't be able to be).