Compared to bulk food grade calcium hydroxide, the aquarium packaged equivalent is not cheap - especially if you are running a larger tank. Ive used both and cannot tell the difference in 'performance'.
So if you can find it I say use it. As stated pickling lime is not readily available in Canada but some people manage to find sources. Ocean Aquatics sells it:
https://www.oceanaquatics.com/view_p...AEPicklingLime