If you want to clean it I'd just soak it in purified water, maybe use a little soap that doesn't have any acids in it like most antibacterial soaps have and use a brush with soft bristles to try and clean out the dirt in the crevices, I've ruined a lot of calcite specimens trying new ways of cleaning, even SIO hasn't worked well with the calcite specimens I've collected so now it's just hot water and soft bristles for me...