Fair enough if one uses 'the modern equivalent', but pneumatic ones will rarely give more than about 30 seconds. Engineering-wise that would be difficult, and they were only ever really intended for illuminating a corridor or flight of stairs etc. whilst one walked through/up it.A pneumatic switch would work in this situation, or the modern equivalent, seeing as you have the neutral there already... In the places I work they are everywhere nowadays, yes they are indeed infuriating, but only because the installers have set them on a 30 second or so timer. If they were set to 10 minutes or more they would be fine though for most applications.
10 minutes ought to be enough for a loo, but I'm not so sure about a bathroom with no window. When they were living at home, my daughters would have had to re-activate it umpteen times before they had finished their shower!
Kind Regards, John
