Good advice on the linseed oil, but I would strongly advise someone to use boiled linseed oil instead of "regular" linseed oil. Otherwise, one could die of old age before the regular linseed oil cures itself to hardness.
Boiled linseed oil contains catalysts that greatly speed up the process of curing (hardening).
On another note, has anyone else noticed, that the cheap bo's coming from the usual wholesale sources (Century, AWMA, et al) have been looking really bad lately?
It seems that most of them arriving are already warped, and those that aren't horribly warped are horribly lop-sided.
Once we get our next shipment of bo's (good quality from a really awesome craftsman), I'm going to use these junk bo's as bashing targets, much like the same way Japanese Sword Arts practitioners use straw mats and pool noodles for tameshigiri.