Cleaning vinegar

Dissolves limescale, soap scum and the dull film hard water leaves on glass. Use it neat on a heavily scaled kettle or showerhead, and one part to three parts water for everyday surfaces.

It needs time rather than force. Ten minutes of contact does more than ten minutes of scrubbing, because what you are removing is a mineral deposit, not dirt.

Never on marble, limestone, travertine or unglazed terracotta: these are calcium-based and an acid dissolves the surface itself. The damage is permanent.

Never mix with bleach — the combination releases chlorine gas. Ventilate when using it neat, and keep it off natural stone worktops and cast iron.