Rabbit chewing

Q. what tips/products would you advise for a rabbit which is chewing wallpaper, carpets, etc?

This can be very difficult to control as it is so natural for a rabbit to chew. Offering something else eg a specific rabbit gnawing toy is one thing, you can coat a foul tasty product onto things that you can eg Bitter Apple Spray or dilute mustard (but not appropriate for all things obviously!). The only other option is to try to educate it into not chewing these things. A loud 'no' when you see it chewing and then giving it the thing you want it to chew instead and lots of praise.

You may need to keep the rabbit in an area where it cant chew until you have broken the habit and where the only thing it can chew is the toy.

There are no magic fixes but I hope a combination of the above helps.