Just remember dogs and cats might have better sense of smell than we do, but we have a whole lot more taste buds compared to them. Also our sense of taste is much more developed.
Guinness's Mom - Have you tried making your own leashes? It is actually not that hard. I have done about a dozen or so in the last three weeks. If you need some ideas or plans on making DIY leashes, drop me a PM. An alternative is a company that has a chewed guarantee. They will replace your leash for you if your dog chews it. They will even replace the replacement leash if your dog chews that one. The leashes are chew proof but if you send it to them, they replace it. Might have to pay for shipping and handling, but if your dog keeps chewing his leashes. It could still work out to be cheaper.
I don't know what the policy on pets.ca is for posting websites of businesses that aren't sponsors so I won't, but if you need information or the name. Again just PM me and I will send you their name and website address via PM.