You can use the same method, but the initial (first time when new) may need to repeat a few times to get it ready. Thereafter, you can use the same method for maintenance.

If those black woks are heavy, most likely, that is cast iron wok. But, again, you can verify with the shop owner.
The material of the wok has little relation to our health. Some people mentioned that there would be a trace amount of iron release into the food each time you cook with cast iron wok and is good for anemic people. However, I have not seen solid studies to support that statement.

If you have a new wok, you have to heat it until it smokes for a longer period. I assume it is the cast iron wok (black color). Then, do as mentioned in the article, but you need to repeat a few times. The surface will become shiny and smooth eventually. It takes a few times of heating up, then cool to get this shinning effect. After that, you can use it as usual and do the seasoning just once after each cooking.

What about those black woks sold in Chinese shops? What caused the black colour? Is it healthy? Is it non-stick? Does it need seasoning?