I use a Nicholson file to deburr 304 tubing, and it's been fine. I'm a long way from a seasoned pro, but I haven't had any weirdness that I know of as a result of the file.
Scotchbrite inside and out if you can, acetone, blah blah, you probably know that stuff already.
I bought one for AL, one for LC and one for SS, and a rat tail for LC that I needed to get out of some jam or the other. I keep the AL file in a sleeve on account of aluminum being real sensitive to contamination and I hate seeing junk floating in my aluminum puddle.
Sent from an earthen ditch outside Needles, CA using an awful lot of low voltage single strand wire.
It's a matter of flour and water and then there's the seasonings, which is a matter of salt and so forth and then you h-we interrupt this for the announc