I've just stripped the sheets off the spare bed, ready for the next round of house guests, due tomorrow. The last left two days ago. It's the downside of owning a comfy "granny flat" without a granny installed. Not that I mind, but it does make for a lot of washing. S suggested I save on laundry by giving the regular guests their own sleeping "insert", those liners used in sleeping bags. "Sheets? They don't need sheets," she said. "It only encourages them to stay longer."

C, who lives in a country house, aka visitor magnet, says she only changes the sheets if the previous guests have stayed more than one night. Or if they're a young, child-free couple likely to have been "active", as she puts it, implying that the rest of us can be counted on to leave the bed in a virginal state. The least troublesome, she says, are single women, who tend to sleep so neatly they just slide out of the bed coverings in the morning as if slipping out of an envelope. She does change pillowcases and towels, however. Standards!

Some weeks I feel as if I'm running a B&B, only not very well. Snowy white bed linen, for example. How to achieve? I ask J, an excellent housekeeper, about grey or yellowing sheets, discoloured by natural body oils, cosmetics and sweat (we give off 25 millilitres per hour, one estimate claims, although how the hell do they measure that?).

So, fix for? "Yellowing?" J says, baffled. "I don't know. Mine are just always white."

I ask P, a laundry master. "Omo and a hot wash," he says, sotto voce, "but I know it's not environmental. Don't tell anyone."