I always use 3-4 drops of baby powder concentrated scented oil in my diaper to keep me baby fresh, although I am a DL, even when wet for as long as 10 hours. A few companies are Barnhouse Blue, Health & Beauty, Eternal Essence, Wah Wash as mentioned by Crinklz Kat, and many others. Just search for "concentrated scented oils." If you don't want a baby powder scent, there are many scents to explore. I never smell like a wet diaper in public, very pleasant to be around, no one knows how wet I am. A word of caution; the scented oil will not cover up a messy diaper.
I messed my wet morning Crinklz Aquanaut diaper 45 minutes ago, a rather small poopie in my diapie but enough to feel a warm, lumpy potty in my diapie. I don't have to change right away or worry about a diaper blow-out so I am going to exercise in my wet and messy morning diaper. I'll change into a North Shore Air Active diaper and plastic pants for a relaxing Sunday.