White distilled vinegar.
It's stronger than your common malt vinegar.
Use it neat in toilets to dissolve limescale.
Put it in a spray bottle with some water and washing up liquid for general cleaning of work surfaces, paintwork, windows etc. Brilliant for putting a shine on stainless steel sinks and chrome taps.
Baking soda / sodium bicarbonate.
An excellent deodoriser.
Sprinkle on carpets and leave for a few minutes, then vacuum up. Removes odours, eg doggy smells.
Use it underarms as a deodorant. I tend to put some handcream or similar on my skin first so that it sticks.
Put it on a damp cloth to wipe inside fridge. Keeps it smelling fresh.