I would say that Canada not having a precedent for vloggers is actually NOT in your favor.
I know that even people that are anchors for the news do not get tax deductions for their wardrobes.... and the CRA is on the lookout for people claiming expenses that are not normally allowed, so you would trigger a lot of scrutiny.
I think you might be able to have a tax write off, if you can show that you do not use the clothing outside of the Vlogger work. Even so, I wonder how all the "unboxing" videos get taxed (or not) for the goods bought. I suppose if you can document that you give away or discard everything that you review, it could work.
Here is an example -- normally condoms are not allowed as tax deductions. However, if you are filming a video or running a sex club that requires condoms, and it is a for-profit business, then condoms are allowed tax deductions, just like medical exam gloves are. Obviously needed for the business, and obviously not used again or keep most of its value after the business use ends.
I think that you would be better off to explain that your expedited shipping or amazon prime charges (to deliver the clothing, to allow faster reviews, when slow shipping is free) are business deductions, but not clothing that you keep.