I'm a long term pain medication user and I suffer badly from congestion as a result. I managed to get one of the promotional sinus rinse bottles for free. It came with one sachet of the nasal rinse sachets and when I used it I could feel an immediate difference, so I went ahead and bought the box of 120 sachets.
Unfortunately now the results are a bit hit and miss. Sometimes I will notice a difference for several hours and sometimes little or no difference at all. Of course this could be down to my condition rather than the product. So I would advise trying this out before buying if possible.