When you store your grinder, what kind of oil do you store your grinding plates and blade in to keep them from rusting? I tried vegetable oil and over time it turned dark brown and plates and blade had a brown build up on them. The last time I stored mine I used olive oil and it still turned a little dark (not as bad as the vegetable oil) and the plates and blade still had a brownish build up on them. Do you think putting the container of oil and plates in the fridge would help? Thanks.