Muzzle to prevent eating things outside?

My puppy has a habit of chewing everything and always wanting something in her mouth. When I she wakes up from her naps and I take her outside she first runs to her toy bin to bring something with her and if she forgets she picks up the first leaf she sees outside. Last week she had to have a surgery for a piece of pastic she found outside and swallowed before I noticed. We're not having success with a leave it command so I was wondering what people thought of a muzzle for outdoor playtime? Have you muzzled your dog and is it something you do regularly or just a part of training?