I tried a while back, and I gave up after the 5th try.. I once got him till 23%, but didn't get close to that on the other tries.. The main problem for me was mainly that he sheeped my tank.. and that sucked .. A LOT! I'm not sure if you can dispell it, didn't think of it back then..

I might try him again soon, If i ever down him, i'll let you know how