dear user about your question i would like to tell you that to have good treatment the cause should detected... these symptoms you mentioned refer mainly to have infection bacterial or allergy that enhance mucus production and nasal rhinorhea..... also there is possibility of having other problems of nose that need investigation and clinical examination but till now you dont need that..........the common cause of that is allergy to odours or smoking that increase histamine production and causes congestion of the nose....... common cold infection is commonly cause that ......he can use saline to gargle his nose and can use saline drops.....nasal spray that he used may have no effect as the cause of that not detected or treated .....as if he has sinus infection he should administrate antibiotics to role out this infection like amoxicillin......also helpful medications such as prednisolone will help improvent alot............. he should also drink alot of warm fluids that will make you better ... getting away from smoking or area of smokers and odours is very important ....some times we require nasal swab for investigation if symptoms get worse but now you not need that................ wish you and him healthy life