depends on you opportuniteies:
Burning would be grand in a cement oven but not at home.
Interring is still a good way. Preferably planting a hungry tree on top.
Feeding to someone (or someting) is grand if you have a shark bassin at home.
Dissolving in nitric acid is a possibility as is dissolving in hot caustic or in a melt. But you would need acces.
Oh and please post the relevant chapter of the mystery you are writing here.