Buy a stainless steel pot scrubber, the ones that (obviously) don't have any soap on them and are relatively coarse. The perfect ones are almost a ribbon-like mesh instead of wire, and are formed in a little donut-like shape. Take that scrubby and put the tip of your auto-siphon throught the hole in the middle. It works perfectly, not a hop leaf one in my fermenters and no clogging at all.
"This song goes out to me because I'm so f*ckin' cool!"~John Reis