Can't find denatured alcohol in Canada, best alternative?

Yeah. The “denatured alcohol” there is just a light organic solvent.

Denatured alcohol is industrial-use ethanol. Any reasonably pure ethanol is a direct substitute. Something like methanol or isopropanol (isopropyl alcohol) is pretty similar.

Any other light organic solvent should work fine, like mineral spirits, kerosene, etc. These tend to go by a lot of different regional names.