I am weary of having to provide any wormer on a regular basis because any worms in the goat's system WILL develop a tolerance for it. But, some natural ways to help keep the load down so you don't have to worm medicinally too often would be, as mentioned, pine trees, pumpkin seeds, black oil sunflower seeds, and copper, provided either at an ideal level daily or as a bolus on a schedule that suits your areas deficiencies. If you provide some or all of these things, maintain a clean pen (there is always going to be berries, just so the best you can to keep it dry and clean), and your goats are overall healthy - fed properly, exercised often, and provided with all necessary vitamins and minerals - you should not need to worm often. By doing fecal tests you can determine if worming is necessary and do only when needed effectively lowering the amount of medicinal wormer you have to use.
Tea Tree Oil is very effective as a topical treatment for lice, mange, and bacterial infections on the skin and feet. At least, that has been my experience. I do not know if it is/isn't safe or effective when taken orally.
I won't launch a full on western medicine versus natural care argument. But I will say this - 200 years ago, well even today in areas of the world who have no access to what we consider western medicine - animals die at astonishing rates. Farmers are lucky to see what we would consider a 50/50 survival rate in kids. The milk is often tainted and makes it's users and drinkers sick. The animals themselves are overrun with parasites and are anemic which of course shortens their life expectancy. It was not a pleasant world for animals being kept in captivity before we began finding ways to treat their problems...
That being said. I firmly believe you should do no harm when caring for your animals. If they don't need it, don't do it. Why overload their bodies with it? And if you can find natural ways to provide your animals with the nutrients they need as well as natural ways to keep them healthy then do so - as long as you don't do it with veld eyes assuming it's the fix all. Sometimes medical wormers are necessary for the well-being of your pets