I've spent a lot of time googling this and that over the last few weeks. When was this invented? And this? And THIS? But of course what really matters is not the date of invention, but when it came into common use... Toilets were invented by the 1850s (they were famously available at the Crystal Palace Exhibition in London) but didn't become common until IIRC the 1880s, because it took some time to figure out how to make them so they didn't smell up the house.

In my youth I went on the opposite journey with margarine and butter; when I was small we used margarine, and then we switched over to butter, and butter was DIFFERENT and I didn't like that. Now of course I am a born-again butter convert, but it took some time.