What I've noticed is after the first dry burn they either gunk up faster or it takes a higher temp to get it to work right. Probably both. They just didn't seem to work any where close to a new coil in flavor or temp. For me tho you can't beat SS for TC and flavor. I've used Ti, NiFe, NI200 which I hated. Maybe it's just me but nothing works like a new coil. Even with Kanthal. But try as I do I still like TC the best for vaping, just more work which I'm not into at present. Maybe I'll give it another try and I may get some 28 and try it. 26 is nice tho. 28 used to be my go to with Kanthal before they got SS to work with TC, I sort of liked Ti for a while but I just threw a new 100' spool of it away. IMO too dangerous.
I've tried 26ga, but 28ga heats faster at 10W. SS316L has been my go to wire for years. I try not to let it heat too much when dry burning. Once it glows dull red the juice is cooked off and I dunk it under the sink tap to cool it, then rub it with my finger and dunk it again . If it's not nice and smooth after that I wind a new one.
I just wet it before dry burning and run the wick back and forth to clean the inside before pulling out the wick.