Buy Naselin Nasal Spray (Xylometazoline HCl 0.1%) Naselin (Xylometazoline Hydrochloride) Spray is a nasal decongestant that quickly relieves stuffy noses by narrowing the blood vessels. This helps to decrease swelling and relieve congestion. In addition to this, it can also help to reduce mucus production, and this further helps to soothe a blocked nose. Many people use it to relieve symptoms caused by a common cold, however, it can also be used to treat nasal symptoms due to sinusitis and allergies (such as hay fever).