One way I've found to get around the gesen bow slow missiles (very similar to what's suggested above) is to equip the quiver of plenty. Make sure it's selected (got the green box around it) and the gesen bow then fires +1 arrows at a much faster rate
and it still carries the electricity damage. Very handy indeed because you don't have to worry about ammo then
Same principle as what others have said by putting other arrows there, but I hate having to carry around ammo
