My method for putting stripes where God didn't, is to buy a 4" disposable paintbrush, ( preferably one with natural bristles) and cut out gaps in the bristles, up near the ferule. I also like to take an exacto knife, with a new blade, and shave the tips of the bristles, so they resemble a pin striping brush. I have found that shoe dye tends to change color, or fade in sunlight. The last couple of trade rifles I did were done with aquafortis, and then heated until the stripes turned almost black. I then neutralized the acid, with a baking soda solution, and did a final sanding after it dried ( it will whisker on some types of wood).
You have to work pretty fast, because the acid will eat up the brush if you dilly dally.
Hungry Horse