You've probably read this before, but just in case you haven't here's Sew-Classic's page on lubes.
http://www.shop.sew-classic.com/4-Oi...e-Tools_c6.htm
Unfortunately they can't (or won't) ship to Canada.
Also here is Tri-Flows web site. You might be able to contact them and get the name of a Canadian supplier.
http://www.triflowlubricants.com/index.html
To answer your question of why all I can do is relate my experiences.
I've used gobs of different oils and greases in my life. Many different ones on firearms, tools, fans, and other equipment. Some worked good, some worked great and some didn't work worth a hoot.
Then we come to sewing machines. Sewing machines do not have bearings, they have shafts in bores and all that stands between them and wear or seizing up is the oil.
In recent months I have rejuvenated a bunch of old decrepit machines. I've used normal sewing machine oil (Singer, Alpha Sew and who knows), Marvel Mystery Oil, Pennzoil light machinery oil, and something amber my wife bought as sewing machine oil.
All the oils worked, but the Tri-Flow was noticeably better. I can feel and hear the difference in how the machine runs with it.
Tri-Flow grease doesn't fling off the gears as Singer grease does, and it's not sticky and rotation inhibiting like the white lithium grease I've tried.
I consider it better than anything I've tried to date on sewing machines.
In lieu of the Tri-Flow products, stick with Singer oil and lube if you can find it. It's not as good as Tri-Flow, but it's a proven sewing machine compatible product.
Joe