I have seen a couple of threads explaing why sucking is a horrible practice, but thought it was generally understood to be unsanitary, and unnecessary.
Even without a syphon, fill the hose with sanitized water (no rinse), let the no rinse pull the beer into the tube, let the no rinse go into a bucket or trash can,move the hose to your keg or bucket when beer runs out.
Syphoning is easy. NEVER SUCK.
Even if that wasn't the problem, it is a bad practice.