Just in case - not that I want to be a scaremonger – in case that the SHTF then how would you wipe your derriere? Of course you can buy a lot of toilet paper in advance put it in the garage to provide some cosy nesting material for mice and rats. How sustainable is our use of toilet paper anyway?
I remember that in my grandmother’s house you had to use newspaper, toilet paper was only allowed for the final wipe. You could use "personal cloths which would be washed just like diapers. I’m not after that. There are some leaves that might do the job, seasonal availability provided:
Woolly Lamb’s Ear (Stachys Byzantina), the leaves are nice and hairy, they seem to be quite small for that purpose.
Hollyhocks (Alcea rosea) have big fuzzy leaves, still a bit small for my taste, but pretty they are. Common Mullein, (Verbascum Thapsus), nice hairy big leaves, however, I don’t know whether there are sufficient leaves produced for daily usage.
The most suitable plant to me seems comfrey (Symphytum spp.). The leaves are produced in abundance; they are big enough, soft and fuzzy.
To be honest and non-sustainable: I really like my toilet paper!