There isn't any "non-magnetic" material. The accretion disk is heated to plasma by friction. The whole mess is a thermal x-ray emitting magnetohydrodynamic nightmare. Ain't conservation laws a bitch?

http://www.funnelworks.com/design.html
http://www.schoolfunnel.com/index2.html
http://www.bigfunnel.com/

Eventually escalating sturm und drang adds up to a burp. Momenta and magnetic fields squirt out, stuff falls into the black hole. Repeat. What does this suggest about "controlled hot fusion?"

Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz3.pdf