Nope. I often use dish soap and a soft scrub pad on my cast iron just like my Grandmother and mother did with those same cast iron pans and dutch oven. A decent seasoning on cast iron is probably more durable than non-stick coatings. Just keep it out of the dishwasher. The high temp hot water and caustic dishwasher detergents WILL damage your seasoning. But, then you just need to re-season to fix it all better again.

My lazy way to keep my cast iron and plain high carbon steel wok properly seasoned is to clean with hot water and mild dish soap then return to the stove top heat on high until hot, then shut the burner off and hit the insides with a light quick spray of cooking oil. Or I just use some plain vegetable oil and wipe on a thin coating with a paper towel. and leave it cool.