I'm surprised at the number of people who use a real number confidently. I just grab enough to feel "safe". I'd guesstimate 4-6 on average of the double thick rolls but never stopped to count.

This might be TMI - and i'm totally serious - but in my case I suffer from severe bleeding if I do dry wipes. I purchase the "ultra-hard" (no flakes) variant of TP, dip about 1/4 of it into a cup of water, fold it in half, and then I wipe. Anywhere from 4-8 wipes, with the last wipe being a dry sheet to pat dry the area. This makes buying "standard" TP problematic for me, because that 1 sheet now turns into 2 or even 4 in order to prevent tearing up the TP during the wipe.

If you only use one sheet you risk poking a hole.

I would guess 3 is a closer to average.

Isn't "poking a hole" the intention?

Unless you fold said single sheet in half.

yes, 2 sheets folded together

4 sheets crumpled up gives much greater surface area, as well as perpendicular folds, with which to grab the target material. Wiping with a flat surface makes no sense at all, and likely requires multiple wipes to achieve the desired result.

I wish there were statistics on the commonality of various wiping techniques.

Yes, but multiple wipes per BM - about 6-8 sheets for me on average.