I see how tru-oil can be worthwhile for presenting a shine and for sealing small pores in wood handles, but I prefer not to use it. A properly stabilized piece of wood or a dense and oily wood should not need tru-oil. Permeable woods shouldn't be used as knife handles, in my opinion.
Tru-oil builds a layer on the wood surface, which when sanded with even very fine grits, tends to dull immediately. This poses issues for me when trying to seal a handle or scale which is directly adjacent to a previously installed metal guard or bolster. After multiple applications of tru-oil, the tru-oil finish bleeds onto the metal guard/bolster surface and must be removed. The result is that the handle scale surface ultimately will be a higher profile than the guard or bolster, and that the sanding can never be kept perfectly accurate to assure that the finish on the wood is not scuffed.
A properly stabilized / ground/ shaped / 800 grit hand sanded wood handle should easily present a brilliant shine after being touched on a 6-inch 1850 rpm cotton buffing wheel with 600-100 grit rouge for no more than a minute or so. This will not result in raised fasteners or pins.
An industrial (6" plus wheel) buffer is highly worthwhile for me. A dremel type buffer is too small for knife handles and will produce divots.