Well I was gonna dose it, I guess .25 tablespoons per 10gallon as I read. Then do a water change about 6-8 hours later. Im googling as we speak but nothing so far about catfish and the salt.
1/4tsb per 10g would be fine, i'd only get worried if you got up to 1tsb/2g or higher. i know a guy who treated his pleco tank for ich using a high concentration of salt and 86* water