Pros: easy, helps eliminate plaque and build up, almost any cat will use it
Cons: not as effective as brushing or gel treatments
This is a product that should be used in addition to brushing or gel treatments. It wont do the full job of keeping the teeth healthy on its own. However, if you have a cat who will just not tolerate brushing or dental care of any kind this is a great hail marry pass in the dental care world.
while it won't keep your pets teeth perfect or anywhere near what brushing can do, it is better then nothing. at the very least it will help reduce the germs and decay that could cause life threatening illness for your little fur ball.
perhaps the greatest feature of this product is that you just have to poor it into their bowl, no holding down or scratched arms needed. My cats are not aware anything is in their water bowl besides water. Some cats, however will be aware that something is amiss with their water.
It is a good idea to set out two bowls of water when first introducing it, one with the additive and one without. If they are drinking the one with the additive in it without problems then you can go back to one dish of water (I keep at least one dish in every major room to encourage them to stay hydrated)
Setting just the additive bowl out when they are refusing to drink it could dehydrate stubborn cats, So make sure to monitor if they are drinking the water and if they are not offer non additive water for them as well. I offer both to my cats in different areas of the house and they drink a little from each of them.
Remember, dental health is very important for cats, but is not more important then proper hydration!