My keloids have grown back larger and they hurt. How effective is dry ice as a treatment? (Photo)

I am African american and I have keloids on both of my jaw lines, one on my ear lobe and a series of keloids on my upper arms and back. I Have had steroid injections in the keloids on my jaw lines and the keloid in my ear lobe. They have grown back larger and they hurt, itch and burn. Can I use a home remedy such as tea tree oil on much older scars? how effective is dry ice in the treatment of keloids?