Could someone please advise on how to prepare driftwood collected from the wild for placement in a freshwater tank? Was told to boil W/ salt. How long? How much salt? Regular salt? Will the salt affect the fish, even though I'll rinse well after boiling? Also, will it float, which I don't want? And, will it sink eventually, or, am I out of luck. I bought a couple of small pieces from the pet store, nice & dark, prepared obviously, but would be costly if I wanted to fill up my tank, which I do. Thanks for the kind assistance!