Whenever I try a bag, my pigs just stand on it and soak it with pee until I take it out, don't seem fussed about boxes either, it's weirdCarrot cottage is a big hit in our house - and a good old cardboard box or a large paper brown bag! You don't need to spend a lot to keep them entertained.
I have one of those for my pigs, they love it and I've never seen a problem
I did notice, pets at home ones are more generous with the carrot coating. But for wilkos price and i live 1 minute walk from wilko, i go there