I have never tried to sharpen one, I suppose it could be done, if one was smart about it. Like with knives, it is wisest not to remove too much metal in creating an edge....
Truthfully, I have never had one dull enough not to work before I lost it.
I get lazy or rushed during work switching from 110 sometimes, and stick the blades in my pocket, instead of back in the tool, they end up in the laundry, and the wife squirrels them away somewhere. I loose more stuff that way.... There is probhably a pile of them stashed in the drawers next to dryer, I'm afaid to look.... I buy more tools that way...
I have seen the electric versions that do four or five pairs at a time. They look a little wieldy to use, but would certailnly cut down on fatigue. However that would be a hand wash, or dryclean only tool, not for me....