[JRTJH]

With the short time that waste is in the tank (for most of us) chemicals are used more to deodorize the holding tank than to aid in breakdown of contents. While there's some breakdown that occurs, there's not really any need to use chemicals unless you notice an unpleasant odor. It won't damage your tank to not use them and it won't hurt to use them even if you have no odor. It's more a personal choice than a necessity.

We do add a cup of cheap olive oil to our tank every year during winterizing as a lubricant for the seals in the dump valves. Other's use commercial seal lubricants others don't add anything. Again, that's a personal choice each of us makes without any "necessary requirement".....