
Hi gumi,
I give garlic 2 or 3 times a week, other than that they get it in our leftovers :) If using fresh they get about 1 clove between 3 but more often than not I use the pre-pulped 'lazy garlic' and they get about quarter of a teaspoon each (medium sized dogs, around 20/24KG)
You can buy odour free tablets but I've not used them personally :)
CH can cause a population explosion if eggs are in nooks and crannies - hence indoors regular vacuuming and steam cleaning around skirting boards is a good idea and of course keeping the dogs' cats well groomed and checked for any evidence of flea dirt.
We have a high population of wildlife using the same parklands (and our gardens) as the dogs - deer, foxes, hedgehogs, squirrels and of course neighbours cats. Despite this all of my dogs over the years have remained flea free as has our home and that's without flea shampoos, stronghold, frontline, sprays, potions, lotions or any chemicals used on the furnishings etc. I just prefer to go down the natural route where possible and have found this works for me and mine :)
HTH, Teri