If you are getting just air and foam, the issue is something isn't sealing properly. I've been using Autosyphons for many years (ever since I learned they exist), and for small volumes they are by far the best solution I've tried. But you do need to take care of them. If your hose is the wrong size, or is not on securely, you will get foam and air going through.
Also, if you store the autosyphon such that the inner cane is resting on the rubber ring at the bottom, it can take a "set" and no longer be round. That will also result in air and foam, though the ring will recover and go back to being round enough if given time to rest without being pressed.
Lastly, when you use your autosyphon, do you press the cane down while the racking is going? If it is extended, that can also result in a leaking seal.