One of my mother-in-law's neighbours works as a cleaner in a hotel on the Costa Blanca. Despite the free mini bottles of shampoo ('amenities' the posh hotels call them, in English, to make them seem posher still), people still buy their own in the airport, and then leave them, practically untouched after a short stay.

She has to remove them, so comes back home with a massive haul of toiletries (and sometimes clothes that tourists have bought, then just left behind, label still on and all), which she hands out to her neighbours.

We haven't had to buy shower gel since my mother-in-law moved in next door to our new third-party hotel supplier. New flavours of fruit and nut extracts every day.