Isopropyl alcohol also reacts differently from a chemical perspective than does denatured alcohol. Fred, I don't meant to be contrarian; I'm just speaking from my own experience. For example, I've had isopropyl alcohol do some nasty things to some plastics (dried out black plastic to the point it turned a very white gray), while DNA does not do this. I haven't tried Isopropyl alcohol on my blanks, mostly because by the time I'm ready for that, I am too excited to want to risk ruining the blank!
Good luck, and if you try Isopropyl on Cocobolo, please let us know how you make out!