Aqua Kem Blue is an easy to use powerful additive for waste holding tanks.
With a pine scent it can be used in Cassette toilets as well as porta pottis. Its formula is derived not only to supress unpleasant smells and reduce gas build-up, but also to break down solids and toilet tissue.
How to use: 
Simply pour 150ml into a 20L waste tank. Add 2-3L of water to ensure optimum performance. Thetford recommends refreshing every 4-5 days.