Shiazo is not tobacco, it is just a mineral, a volcanic rock that carries molasses mixed with aroma. So in many ways it is healthier than hookah tobacco: It contains no nicotine. It contains no tar. It also avoids countless other unhealthy substances, so it's not even comparable to tobacco.
It can be used more than once. One can of Shiazo mineral can be used several times! After repeated use, it is worth boiling and re-flavouring.
One can contains 100g. Since it can be reused 4-5 times, 1 can of Shiazo mineral and 1 tube of flavouring is enough for 500g of Shiazo. Tobacco prices are constantly rising, Shiazo mineral is not subject to excise duty, so you can buy Shiazo cheaper than hookah tobacco! There is no age limit for consumption.