Yes, use two spectra cored lines each tied to a double 16 mm Harken air block. On one side tie a bowline... On the other put about a half inch diamter stopper ball (also tied to the double 16 mm air block). Adjust the lengths of the spectra cored line so that the loop with the captured ball are on either side of the sail cringle and long enough so your double blocks don't bottom out at max downhaul. We store the downhaul by putting the bowline knot into the mast groove and the ball back in the loop and taking the slack out of the downhaul to keep it taut on the mast.

We use a 1/4 inch line for the down haul which is led back into the front beam and bungeed to the other side for a take up.

Take Care
Mark