If he's marking (releasing small amounts of urine throughout the house) neutering is the best way to solve it. In this situation, neutering works 99% of the time. In the other 1%, we recommend using a "belly band" which wraps around the waist and covers the penis, making it impossible for him to mark.
Before I do anything, I would see the vet to rule out a medical cause for the behavior. He could have a urinary tract infection or urinary stones that are causing irritation. Both are painful.
If you rule this out, you can then start behavior modification.
Let me know if you still have questions.
