What caused your alloy bear magnetism?
If it is annealed/stablized condition, you are having intrinsic magnetism that cannot be removed permanently even by thermal demag.
if it is cold worked/ quenched etc that caused disorder (strain/segregation/Fe rich cluster), and so magnetism, only thermal anneal can remove it.
Both cases, you can do what Mike recommends to de-mag, but only temporarily. When it exposes to an external magnetic field again, it will re-gain magnetism.
If it is a small part your demag unit may work.
But the material is still ferromagnetic, so it will respond to any magnetic field.
In my experience any Cu based alloy with over 2% Fe will be ferromagnetic, below this amount it can be kept in solution.