But that's exactly what the household did when shopkeeper John Seabright was approached by two thugs while working at a Londis shop in Gloustershire.
The frightening brutes were wearing balaclavas and welding hammers, and they demanded the 62-year-old open the till and hand over cash.
John, who has worked at the store for 15 years, was with colleague Tim Wilsdon, 21, at the time, and Tim ushered scared customers into the shop's bakery to hide.
Seeing no other way to defend himself, John then grabbed the £1 cleaning spray and squirted one of the thieves in the eyes.
John was quoted in The Daily Express, saying: "Another customer tried to tackle him and I tried to grab the hammer but didn't get it.
"I saw some cleaning spray so picked it up and sprayed him in the eyes. It must have hurt because that was it – him and his mate scarpered."
John's wife Sheila, 70, was anxious her hubby had tackled the yobs, but added: "I'm proud of him through, really proud."
Well done, John - and Mr Muscle!
By Alice Hughes
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