If I remember correctly, you're wanting to avoid most chemicals, right? I thought I remembered you saying one of the products made her itchy, maybe I'm mistaken, but if this is the case, you may search for a product from Ark Naturals that's made from neem oil. The neem helps soothe the skin, and it also has citronella and some other natural products that help supposedly repel fleas, ticks, and mosquitos. I tried it, it does nothing for ticks, but it did help with mosquitos. In fact, I spray it on myself when we go walking. Jes is back on Frontline, because he has to have some sort of protection against ticks.
More than likely, you'll have much better luck with the K9 Advantix, but the Ark Naturals may be worth a try if you don't want to use the K9 Advantix.