Neil Slade's original writings about refilling described his technique for refilling "on the fly." I did that for more than a year. Remove the nearly empty cart, put a (gloved in my case) finger over the ink outlet, open the fill hole, refill, seal the fill hole, remove your finger from the outlet and let it drip till it stops, blot the outlet against a paper towel that is on a flat surface so you dont dry out the filter in the ink outlet, and put it back into the printer. With the Howard squeeze bottles this takes less than two minutes.