I've been in emergency situations with amphibians that required me to touch them with my hands- I did get them wet first but they really were fine. I watched them very carefully for a week or two. We're talking less than paper thin skin. You're really not going to damage the slime coat on a fish with scales unless you're trying to. Just keep your hands wet and make sure you rinse the soap off REALLY WELL before putting dish soap hands in their water- I prefer (wet)hands to netting actually there's less chance of fin or scale damage that way. I'll never net a catfish on purpose I'm not trying to eat.
