There is a product, Bitter Yuck, sold in pet supply stores and online as a no chew spray to discourage cats and dogs from chewing on electronics wiring or anything else you don’t want your pet chewing.
A dear friend used it according to the instructions on the package, being careful not to use more than recommended, to stop her cat from chewing the wires to her computer equipment. That was back in March. Her cat immediately got dangerously sick, apparently poisoned, from ingesting some of the Bitter Yuck when the cat tried chewing the wires after the Bitter Yuck was applied.
Sadly, the Bitter Yuck caused permanent kidney and liver damage. Her poor cat has been increasingly ill ever since and has now died.
At the time of the initial poisoning from Bitter Yuck, my friend contacted the company that makes the product and talked with several company representatives as well as doing considerable research about the product. It turns out that one of the ingredients is known to be highly toxic to cats. The company knows this and one person there even admitted that verbally to my friend although, of course, not officially and not in writing. Despite that, the company continues to include that ingredient as a bittering agent. If I recall it is one of the variations of rosemary oil. There actually are several different compounds that have that common name and at least one of them is lethally toxic to cats.
So please, please, please do not use Bitter Yuck and be extremely wary of using any other commercially produced bittering agent to prevent your cats or other pets from chewing wires.
Please, no one else end up poisoning their precious pets and condemning them to a miserable death from kidney or liver or other internal organ failure caused by this horrid product!