It should definitely help.. I didn't get my little man neutered until about a year old and he had already established the bad habbit
BUT it did significantly reduce it and now every time I see him lift his leg I just give him a firm "No!" and he looks at me all innocent like "what mommy? I wasn't going to do anything" lol so yes it will help, but if your little man is already doing it now, then you will have to still keep an eye on him and tell him no every time he goes to do it (which should not be often)