I've also heard the same said about garlic: semi crush a whole head of garlic, in one of those net things they sell them in, then hang in kennel: if you can bear the smell! Garlic is a powerful antiseptic, very powerful indeed: not to be used on wounds:ouch!! It burns skin if it comes into prolonged contact so keep well away from dogs.
I always add garlic to the dogs food a few times a week and very rarely have any kind of parasite problems or other health problems with the dogs .