A quick question from a newbie. If I could get to the top and bottom of lines, would it be possible keep a bucket of your chosen cleaning liquid at the top (raised above the line) and connect it at the bottom via a small pump (perhaps Sur-Flo) and fully (draw) charge the lines with the cleaning solution. Let set as Dr. Perkins has suggested for a set time and then release everything to allow gravity to pull fluid to the bottom. Perhaps do the same thing with water once you're finished in order to flush out remaining liquid. Obviously this would still involve the work needed with your drops.