Student or Learner
Is it common to say "toilet tissue" to mean "toilet paper"?
In the US, the only people I know of who call it "toilet tissue" (versus "toilet paper") are the manufacturers.
However, we wipe our nose with a 'facial tissue' and not with a 'facial paper'! If we align our bathroom products by melodious titles, 'toilet tissue' and 'facial tissue' would be excellent choices!
We just refer to the thing you wipe your nose with as a "tissue".
Pass me a tissue.
I've bought a box of tissues.
We've run out of tissues.
We would know whether someone was talking about toilet tissue or facial tissue by the use of a/the/some.
Pass me some tissue = toilet paper
Pass me a tissue = facial tissue
Pass me some tissues = facial tissues
Then of course there's kitchen roll/kitchen paper. I don't think it's called kitchen tissue anywhere.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.