Does TCA Work on Scars & Why Isn't It Covered Under Bluecross/blueshield Medicare Advantage?

Hi, I am a 50 year old African American with smooth dark spots left from chicken pox that I had when I was 10. Throughout the years I have worn long sleeves even in the summer. I also have genetic disorder called trimethylaminuria, which worsened leaving me with a hideous smell, where keeping a job was impossible, I've loss over 8 jobs, 3 homes, and ultimately homeless(No job-no income- cannot pay bills rent, etc). Other scars are from bug bites which left marks from me sleeping by buildings shelters complained of odor so I slept outside I now am stable(on disability) and have bluecross/blueshield medicare advantage but insurance does not cover dermtology to remove scars. I have thought to do a TCA at home chemical peel, because I cannot afford the price of a dermatologist for other proceedures. How safe is this and can I use a numbing cream for pain? Hopefully iontophoresis machine treatments will help trimethylaminuria so I can work again, I miss that. But now in an apartment where I am thankful for none the less.