Old testament stuff – Fire and brimstone coming down from the skies! This post makes their case, that using mild soap to clean a pan is fine, by describing what it would actually take to remove the seasoning from a cast iron pan. I also agree, you don’t need fancy flax seed oil to maintain the seasoning; canola oil works just as well.
No, if you wanted to remove the seasoning, you’d need to either scour it with something very abrasive, like steel wool; heat it at a very high temperature for an extended period of time without any fat in it; soak it in a strong lye solution; or strip it via electrolysis. Suffice it to say, it takes quite a bit of effort to actually take the seasoning off a cast iron pan.