Thanks. I had never heard of washing saw chains before sharping until this thread. I guess it is just one of those YouTube myths.
Not a myth here. I told you earlier that I use a grease remover solvent or usually oven cleaner to clean the chains before sharpening then rinse the chains in water ( not soap and water) and let them dry or use an air hose if I'm in a hurry. And this started way before You-tube or the internet was ever heard of.
Did you ever file a piece of metal through grease? What happens to the abrasive action of the file?
You can soak and clean a file somewhat but you can't clean the little grinding wheels. The only recourse is grinding them down with the shaper stone.
The wheels are not very large in diameter in the first place and the usable diameter distance from wear is very small since the motor head
gets in the way with not much wheel loss. It's like a radial arm saw. You might have a 10" blade but the depth of cut is only from the bottom of the motor to the blade tip.
I also did say that I soak and store my chains in oil afterwards to keep the rivets free and prevent any rust.
Some mechanics are sloppy, use screwdrivers to pound out pins, torque important fasteners by feel, and spend a lot of money replacing tools as a result. You didn't give the impression that you were that way.
With the saw grinder on a greasy/oily gunked up with wood chain you will not only cause burning on the teeth but soon have a black grease impregnated pink stone that is not cheap to replace.
When you spend time and money taking your chains to have them sharpened they don't have time to do it right, just get it done fast and eat a lot of tooth while doing it. They buy grinding wheels by the box, but guess who is paying for them?
Most folks that maintain their own saws, whether by file, machine, or a combination do so to get a chain that cuts extremely well and can be sharpened many times over.
Just like your students, you can tell them the best way without going into great detail as to why, but they will try shortcuts until someday
they will admit to themselves that old Gale wasn't so dumb after all.