Interesting topic.
Just an addendum for foreigners: I've been often in the States, and I know how really supersoft most kinds of toilet paper there. But here in good old Europe, the vast majority of (cheap, supermarket brand) TP is made from recycling paper. Don't use this for cleaning the screen of an ereader!
But of course the idea with pumice-free "supersoft paper" is perfect - but as mentioned above, one should use so called "cosmetic tissue paper" instead. These have the very same quality like the better American TPs and are therefore perfectly suited for that purpose...
And of course there are predamped "lens cleaning/eyeglasses" papers in wet boxes. They're also fine (but much more expensive than cosmetic tissue paper).