Technically, I think you're pretty much stuck. It is expressly provided for in the Tax Act that interest on a loan to acquire assets for the purpose of deriving capital gains is not deductible. (I think it was the old s.51A but not sure now).
The whole premise behind claiming interest as a deduction is that you derive dividend income. That's the income against which you claim the interest deduction. It doesn't matter whether it's a ML loan or a personal loan - you will struggle with both. Having said that, you could always argue that your intention is investing for divvy yields (regardless of whether they are paid - like a Total Holdings Case scenario) but a better bet would be to borrow to invest in some mid cap growth fund which do pay distributions.
