I've been giving this a lot of thought lately.....

Last year I had three runs of 3/16". When I pulled it I ditched all the short lengths of tubing, the Ts and spiles. I kept the longer lengths of tubing and washed them out by laying them down the hill, putting the ends in a 5-gallon pail and let water flow through them for a couple hours. I simply left a hose in the bucket to refill as the water drained through the tubing. Still, there was a lot of waste that I felt badly about, let-alone the cost.

This year I have a different plan. I'm going to run all my tubing and map them out on my land. (I will pull all the tubing down at the end of the season just like last year) Each tubing/T/drop set will be labeled so I can reuse them in the same location next year. I'm going to pull all the tubing sets out in one piece, lay them out across the lawn and run pressurized water through them for a number of hours. I've made a manifold up that I will connect all the terminal ends to and run a garden hose to. I will put each spile back into its cup at the T and pull them off one-by-one letting the water flow through each drop. When I'm happy that they're clean enough I will run compressed air through the lines and un-cup each spile just like I did with the water. When the whole line is clean and dry I will cut the spiles off the drops, roll each run on its own spool and put them away until next year.

Next season, roll each run out, insert new spiles into each drop and string it up. The only expense will be some time and new spiles each year.

Here's the manifold. Just mocked-up for now. Need to tape and tighten everything down.