Clean the nose using Physiological Spray Solution ( sea watter)
Spray this
in to the Nose , wait 1 min, vac the nose using s soft squise
nasal pump if the child is not able to blow his nose.
This spray is a physiological solution and can be used over a longer period of time, but be warned that it contains small amounts of salts.
After the nose is clean you can use some of the children nasal sprays like 0.