How do you best clean a cast iron skillet?

I just got a cast iron skillet as a gift and seasoned it properly. I’ve been making grilled cheese in it and just rinsing and wiping it out. I want to make some fish for dinner but I’ve heard you can’t use soap on a cast iron skillet or else everything after will taste like soap, especially because it’s newer. It sounds disgusting to cook meat and just wipe it out or rinse it with boiling water. Please help!