Atleast one "natural" product to help with sinus related issues is called Xlear. Xlear utilizes xylitol in its product.

According to Wikipedia xylitol has several medical uses including:

Diabetes

Possessing approximately 40% less food energy,^[15] xylitol is a low-calorie alternative to table sugar. Absorbed more slowly than sugar, it does not contribute to high blood sugar levels or the resulting hyperglycemia caused by insufficient insulin response.

Osteoporosis

Xylitol also has potential as a treatment for osteoporosis. A group of Finnish researchers has found that dietary xylitol prevents weakening of bones in laboratory rats, and actually improves bone density.^[16][17]

Ear and upper respiratory infections

Studies have shown that xylitol chewing gum can help prevent ear infections^[18] (acute otitis media); the act of chewing and swallowing assists with the disposal of earwax and clearing the middle ear, whilst the presence of xylitol prevents the growth of bacteria in the eustachian tubes (auditory tubes or pharyngotympanic tubes) which connect the nose and ear.^[19] When bacteria enter the body they hold on to the tissues by hanging on to a variety of sugar complexes. The open nature of xylitol and its ability to form many different sugar-like structures appears to interfere with the ability of many bacteria to adhere.^[20] In a double-blind randomized controlled trial, saline solutions of xylitol significantly reduced the number of nasal coagulase-negative Staphylococcus bacteria. The researchers attributed the benefits to the increased effectiveness of endogenous (naturally present in the body) antimicrobial factors.^[21]

Infection

In rats, xylitol has been found to increase the activity of neutrophils, the white blood cells involved in fighting many bacteria. This effect seems to be quite broad, acting even in cases such as general sepsis. ^[22]

Candida yeast

A recent report suggests that consumption of xylitol may help control oral infections of Candida yeast; in contrast, galactose, glucose, and sucrose may increase proliferation.^[23]

Benefits for pregnant or nursing women

Xylitol is not only safe for pregnant and nursing women, but studies show that regular use significantly reduces the probability of transmitting the Streptococcus mutans bacteria, which is responsible for tooth decay, from mother to child during the first two years of life by as much as 80%.^[24]