Help with seasoning cast iron wok I recently bought a cast iron wok and attempted to season twice.

The first time i seasoned it i think i overheated the wok and it started to smoke when i added oil and some shiny black stains which looks like patina formed.

I tried seasoning a second time but after seasoning, it didn't seem that non stick to me.

Here are the steps i took to season the wok.

1) Scrub thoroughly with hot water and soap

2) on low to medium heat evaporate all the water 

3) add in oil and stir fry some onions (some videos say it gets rid of the initial metallic taste)

4) after 5-10 mins i took it off the heat and let it cool

5) i rinsed it with water after and applied a thin layer of oil

This is the first time i'm seasoning a wok and i have no idea if is working out but i noticed that everytime i wipe it with some tissue paper, the tissue paper turns black! I'm considering throwing it away and any help would be appreciated.
Cast iron is has pours. Oil sinks into them. So oil. let set- Heat till smoking in oven is best. Remove &amp; reoil let set to cool. Never use soap on cast iron. It removes the oil that has sunk in. The more you use them the deeper the oil soaks into them. To clean. While hot add water. scrape out. Or wipe out. Dry reoil with salted rag or paper just wipe with oil salt on rag. It will remove some carbon. The black you see.  let set. This is not the advised way. But works for me.