“How effective are natural remedies in treating a toothache?”

No. See your dentist

There are many reasons for you to have a toothache. Only a licensed dentist in your area can assess your oral health and properly diagnose your problem. The best "natural remedy" is a visit with your dentist. Clove oil can sometimes provide temporary relief, but it is not a "cure" nor a "treatment". Dental conditions always come back and usually get much worse without dental treatment (and also cost more to fix).

Natural remedies do not work at all unless there is a gaping hole. Pain is nature's way of telling you something's wrong. Go see a dentist before it becomes worse, and it can get much worse.