Hi again,
as far as adverse effects on a firesteel goes, I own 1 scout version which has been around my neck for a good 15+ months for 6-10 hours a day.... and 2 army models, 1 in my coat pocket with the rest of PSK and 1 in my camping/BOB.
I have just started in non destructive testing and whilst in training I have subjected all 3 to a fluorescent dye penetrant test. Under inspection, none of them has shown any 'pitting' (small holes) so nothing has leached out into clothing or even my skin. No big deal but I do sweat a lot as I'm a hairy fitness instructor. so when I say sweat, even when I don't exercise, I sweat.....blah blah etc
Summary no damage to mine except where I have run BK10/Leatherman blades on them when I've been playing