What's the meaning of "alternate together"?

I just bought 2 different bottles of cream and the instruction says "use them separately or alternate together morning and evening".

I can't quite catch it. Isn't "alternate" meant you have to do two different things at separately? So how come "together" goes immediately after "alternate"? In fact, before I read the instruction, I'd been asking if I can use the 2 creams at the same time. Is that what it meant?