Toilet bowl cleaner (the works) has HCl and it doesn't react with ammonia like hypochlorite

You can also use windex, which already has ammonia.

Or vinegar, acetic acid

Even alcohol can help with the waxy sticky compounds in the urine

You told him to do it, but you didn't say to make a dilution or already have a dilution on hand, perhaps that's on you, Basic Chemistry.

Great for sanitizing, not the best cleaner though.