The problem is sourcing it and cost. It works a treat but it is hardly available in Tesco. Online you have postage etc.

there re also concerns that dogs ate it and were dying as a consequence. It is still available in some of the large garden centres near me.

They use it a lot in the US and I think it can look good. Perhaps it is too windy here? Not seen lots of dead dogs piling up in the streets of the US so I wonder how right that is?

It is correct, Botanic, cocoa shells can be at least toxic if not fatal for dogs, but like everything else, it depends how much the dog eats and how big the dog is. Caffeine and theobromine contained in the shells is highly toxic to dogs, but the levels of the latter within the mulch varies depending on the source and brand. Mostly its small dogs and puppies that are at high risk, but again, a little nibble will likely only produce gastro intestinal symptoms. As an example, a 501b dog would need to eat 9 ounces or more for death to occur, between 5 and 6 ounces for seizures to occur, again depending on the brand of shells.

I'm not sure that theobromine was the issue as it dissipates within a few days, so relatively easy to keep your dog away from it if you had concerns. And it didn't blow about because after spreading it you damped it down and the pieces bonded together. It always looked better for longer than bark.
I was looking online for it and found a couple of sites which listed it but stated that it was out of stock and they didn't know when they would have it again.

Urbanite - whenever I put information on this site (or any other, come to that), that information is checked and double checked (against more than one source) on the day that I post it. So if that's what I've said, that's what the information is. I make mistakes sometimes with stuff I've known, but not used for years, and occasionally have a 'brain slip', but I don't make mistakes with stuff I've just looked up....

And regarding cocoa shells, the chocolate smell is strongest when its first laid, it seems to dissipate over time - which means that a dog will find it extremely attractive for the first week or so, when presumably, the levels of both toxins are highest.

So you agree that the theobromine dissipates? And if that"s the case then anyone concerned should keep their dog away from it for a few days.
I remember using this in the past - it was great around hostas for helping to keep the slugs at bay and wildlife-friendly unlike slug pellets. I don't recall my dog being particularly attracted to it though she was very fond of chocolate.