What are the benefits of herbal sauna?

Does anybody know what the body stands to gain from a herbal sauna? I’ll be spending some time in the Bophut Hotels which I am told provide herbal saunas. I am in love with everything natural, from organic food to natural skin care products and can never wait to try anything that is devoid of chemicals. What ingredients are used in a herbal sauna and how does it benefit the body? I am also wondering if this sauna is any better than conventional ones and the comparative price costs. Can someone please offer assistance?