This is a fairly interesting idea. You would sanitize by putting sanitizer a bucket and siphoning that before the wort. The only thing I would worry about is the integrity of the 20' hose. It's been a long time since I took a fluids class, but there might be a risk of a cheap hose collapsing if there is too much vaccuum at the top. If you buy a reasonably thick hose, you would be fine, but the cheap stuff at Home Depot might not work.