Step 4 literally says to scrub until all of the brown bits are gone. Look at the picture in step 5, does that look like anything is burnt onto it? I see nothing in that says anything about taste.

Also, wikiHow is a garbage source as anyone can submit anything they want. They don’t have to have any clue what they’re talking about.

Here is cooks illustrated, a well respected cooking magazine that tests everything, talking cleaning.

And yes, they say soap is fine. If mild dish detergent is removing your seasoning, it wasn’t seasoned properly.