Thanks Stan, that confirms a lot of my speculative thoughts on kigoroshi. I don't use it very much at all and my feeling has been as you noted; always softwoods and primarily in conjunction with wood that will be in contact with water.

I recall we had discussed it briefly with regard to chisel handles and hammer handles and both were considered a no-no because it damages hardwoods in a way which they do not recover from and so should not be used on hardwoods at all.