Ok, I'm back from holiday, and ready to blog.
First thing: why can't you flush loo paper down the loo in Greece? I wondered about this quite a lot, it is very odd. Which part of the system is so susceptible to blockage?
It can't be the loo itself, because they (appear to be) exactly the same as the loos you see anywhere in Western Europe.
The pipes within the house? But why? The villa we stayed in seemed fairly new (certainly less than 10yrs old, maybe less than 5), why use narrow diameter pipe if you are designing a modern building from scratch? (You do sometimes use narrow diameter soil pipe in the UK where you are converting an awkward space into bathroom, but then you just add a saniflo to mash and pump everything.)
I didn't risk testing whether this is just a myth, but I did ask our tour operator's rep about it: she said that every year some clients do ignore the instruction, and sure enough the drains get blocked. She (understandably) didn't know which bit of the system got blocked.
Could it be the actual sewage treatment system, not the house drainage? But surely most houses will be using a local septic tank, they can't all be on mains drainage on a mountainous island like Corfu.
I recall Yugoslavia (as it was then) had the same issue with loo-paper-down-the-loo. But of other countries in roughly this area that I have visited (Bulgaria, Romania, Italy, Turkey) I am fairly sure none of them have this problem.
I couldn't really figure it out. Anyone know?