just fly it under some high-tension powerlines (remove your mag . compass first! )
that'll cure the bugger
May kill you too! but that's another issue...
On a serious note, degaussing requires a powerful AC field to be gradually weakened.....usual method is to put a large electromagnet near the item to be degaussed, switch on then move slowly away until the emitted field is too weak to affect the subject -matter.
Maybe a scrapyard with a crane-mounted magnet would do it?
DC is no good, it straightens the magnetic "grain" of the subject-matter and weakening the field doesn't affect that alignment....AC "stirs" the poles and as the field weakens, leaves the magnetic structure randomly orientated.
Hope this helps!