Kids’ portable urinals (Travel John brand) (West Croydon CR0)

These are super-clever little things that you can let your kids wee into if there’s no convenient toilet, and the stuff inside turns the liquid into a gel so you can safely put the whole thing in a bag and dispose of it later. Five left from a six-pack. These are several years old but there doesn’t seem to be an expiry date.

Pick up between 9am and 5pm any day except Thursday and Sunday. Location is 3 minutes' walk from West Croydon Station. Priority given to people who are nearby, and who tell me in their first message exactly when (date and time) they want to come.