Doesn't completely destroy bone, but makes them very brittle. To be extra careful you could strain out the bones and crush em up. Slury if you use enough. Since it's just lye and water, it's pretty easy to make a bunch. They would get investigated if it was somehow discovered. Even then, the case woulud go cold before it was even opened. Unless you added in a shit load of your own DNA samples into the slury before you dumped it.