I used honey for my two year old and it really works. Cough mixtures made with honey is also really effective and also helps for irritating coughs caused by allergies.
I haven't tried it but have heard people say that this works, locally made honey is lovely anyway!
For a 4year old, i strongly think it's a bad idea. This is because it still might have pollen grains if it has not been processed. Even when administering it, you should be cautious, as my mom is allergic to locaaly made honey.