Sanitizing long instruments (spoons, auto-siphons, etc.) is always a pain. I was using a wall paper glue tray, but it wasn't quite long enough and my auto-siphon would stick out of one end.
When looking for a solution, I stumbled across the idea to use a windosill planter box instead of the wall paper tray. I was unable to locate a suitable vessle at either my local Home Depot or Lowes, so I started looking around online.
I found this one on Amazon and it works perfectly for my needs as it is 36" long and sealed on the bottom.