John K Jordan
You can do it hand-held also. I use the flat side of a small Dremel metal cutting disk like this: https://smile.amazon.com/Dremel-409-Cut-Off-Wheel/dp/B00T0PBLMW
I generally sharpen a 3tpi or 4 tpi blade 3-5 times before I discard it. I don't sharpen blades with more teeth since my blades are 11'10" long and it takes too long.
The quality of the cut can degrade a bit with multiple sharpenings but most of my bandsaw use is for preparing woodturning blanks so it doesn't affect me.