I think that first of all, wait until you get your knife; the handles may be fine the way they are. I've been using wood handled knives for decades on all sorts of game, and never found wood to any more slippery than most other non-rubber/kraton/ thermoplastic with inserts type stuff. The shape of the handle has a lot to do with how a knife handles when blood and guts covered.
If you feel that you need to try and improve on that handle, then I agree with Jeff's solution up to a point...I truly dislike boiled linseed oil on any kind of wood; be it gun or knife. Actually though, it might work. Since boiled linseed oil never really dries, it might give you a constant, slightly tacky grip. That might work, come to think of it. The only oil finish I use anymore is Watco's Teak Oil; which is a marine oil finish with penetrator's and driers added to allow the finish to get deep into dense woods such as teak and mahogony. Only takes two coats usually, and each coat dries in about 8-10 hours. Of course, both Linspeed and tru-oil are also two linseed oil finishes which also have driers added to them; but I never much cared for their looks. Anyway you look at it, your friend might be overstating the case a bit and you might be perfectly satisfied with the blade as is. We all have our own perceptions about things.
