If you do not want a flea medicine you can put the cat or dog also in the water. keep head above water. Over time, you see the fleas crawling to the head. Then, briefly drowning the head .De fleas. At my young kittens (which I therefore prefer to give no chemical stuff) this works perfect.Pay atention! Eggs are not destroyed, so if you really bothering you, I would just use a good flea medicine.