Alternating toners?

Hello

I have a Canon LBP7100 colour laser printer.

Now I bought a generic black toner a while back, but it produces a slight horizontal line when it prints a page.
So I took it out and sealed it in a bag. Replaced with a genuine black toner.
Colours have all been replaced as genuine since that.

Now, I want to print off a large quantity of black only pages and the line wouldn't be an issue.

What would happen if I took out the existing toners and just put in the black one to use?
Would the...

Alternating toners?