Hi folks. Cleaning up a very dirty Optimus 8R and it's really black. My usual citric acid bath isn't moving it. Tried a bit steel wool and it's very slow. So, if I use my ultrasound machine everything will smell of fuel!! Can I use a small metal cup and put jet etc into it? not sure if it will work! Also taken the wick out of the fuel tube and the brass gauze is stuck inside. I tried blowing through with finger over regulator hole and no air comes out at all. I'll try the blow torch and quench method and see what happens. Thanks in advance.