My Dalmatian puppy eats everything-help!

We have a sweet Dalmatian female just turning 1 year. She’s spayed, in good health, and a real darling in all ways, but with a major, worrying bad habit – she will eat just about anything! She is pretty much through her phase of chewing on everything, during which she ate a leather shoelace and a woman’s knee hi opaque stocking, also paper towels and tissues (she’s passed them in her poop) – she will snatch these out of the dryer or tissues out of a hand or pocket, so we are in control of those, but in our yard, there are broken horse chestnut shells from a tree in the back of the yard. The squirrels drop the nuts into the front of the yard where the dog runs, and despite our best and constant efforts, she will find the shells, chew on them, requiring us to command “drop it” which she ignores, runs, and we have to catch her and force the shells out of her mouth before she swallows them. She also insists on picking up the small pine cones -too big to swallow, but still, we have to remove them from her mouth, small stones, leaves, twigs, etc, etc. Even when she’s on the leash, she will find something to pick up. We are concerned that something she swallows will hurt her internally, or make her very ill. She has plenty of toys, gets quality treats for behavior training, has plenty of fresh water, and is fed a very high quality food that she likes. My latest suggestion is to muzzle her in while the yard, but hubby is hesitant. Help, please!!