This was one of our first zero-waste switches. I couldn't find it locally, so it was one of the few things I ordered from amazon. A big cardboard box full of paper-wrapped toilet paper arrived at our doorstep...no plastic was included. Smaller amounts are available too, if storage is an issue. Now I buy it from our local Whole Foods...12 at a time...and we get a case discount. Find a retailer in your area (USA, Canada, + UK) with the locator.
Switches like this are easy enough to form into habit. One choice at a time. :)