It is almost impossible because the main method shorting taken...

It is almost impossible because the main method shorting taken place is via margin lenders requiring that customers who have gone long the stock (on margin) have the potential for their stock to be lent out (as required) to those who want to go short, which is part of the T&C's of the margin lender. Since nearly all margin lenders don't accept CAN as collateral as it's too risky, then it's very hard to go short unless you find an exotic margin lender allowing it to be used as collateral. I don't know of any.

The other way, and this isn't reported in any short sell stats is to use a CFD provider like IG or maybe Plus500, they use their own OTC market to allow you to go short, however they'd only allow it if they were net long (i.e. some of their clients were long CAN) as they aren't able to net go short for the reasons above.