A puppy chewing the sofa is not being naughty. It is doing the one thing available to it for finding out what the world is made of, and it has months of teeth ahead of it. The problem is not the behaviour, it is that the behaviour keeps choosing expensive targets.

The answer here is two ingredients long: purified water and Bitrex. Bitrex is a bitterant and it does nothing except taste appalling, so the logic is blunt — spray the thing that keeps getting chewed, and the thing stops being worth chewing. Simple Solution list it for furniture and anything else in the firing line, and also for discouraging chewing and licking at skin, hot spots, bandages or stitches. Their instruction is to apply liberally to the affected area and repeat as necessary, and to test a small patch first for colourfastness. 500ML bottle.

• 500ML bottle
• Two ingredients: purified water and Bitrex
• For furniture and other items being chewed or gnawed
• Also listed for discouraging chewing and licking at skin, hot spots, bandages and stitches
• Apply liberally to the area, and repeat as necessary
• Test a small surface area first for colourfastness

A deterrent is not training. A bitter spray changes what one object tastes like; it changes nothing about why the dog is chewing. Boredom, teething, separation distress and pain all look identical from the outside and only one of them is solved by a bottle — so if the chewing is sudden, obsessive, or aimed at the dog's own body, that is a conversation with your vet or a behaviourist rather than a shopping decision. On the practical side, no coverage figure and no reapplication interval has been supplied, so how far 500ML goes and how often you go back over it is guesswork, and dogs differ enormously in how much they mind a bitter taste. Test somewhere hidden first — the maker asks you to, and a stained sofa is a worse result than a chewed one.

Who it's for: owners of a teething puppy with one or two favourite targets, and anyone protecting a specific thing — a table leg, a skirting board, a dressing — rather than trying to solve chewing in general.