No need for anything special or RO for curing it.
Save some legwork and just put the rock into the top tank of your toilets in your home.
Through the normal process of when flushing the toilet the water is constantly changed out saving you the trouble.
It will displace some water in the toilet's tank so dont FILL the tank with it as you could see a decrease in "Log Power" but thats why split it into two or three different tanks and should be ready to go in a few weeks.
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Since it displaces water in the tank it WILL save water so hide behind that if someone questions it. Say your doing your part to save the planet....One log at a time!
-RFB