What form of kava is strongest?

I'm curious to know, in the realm of traditional Polynesian beverages, which form of kava is considered the strongest? Is it the traditional preparation method using a mortar and pestle, or has modern technology perhaps introduced stronger forms, such as concentrated extracts or powdered mixes? Does the type of kava root, its freshness, or the brewing process play a significant role in determining its potency? And for those who have tried various forms, what is your personal experience in terms of strength and effects? I'm eager to learn more about this fascinating beverage and its varying strengths.