Mammoth Flossy chews have been a lifesaver for me training Lucy; I recommend them now to anyone I know who's having trouble with their dogs unruly mouth.

Sold primarily online (they sell them in pet stores by me, but I'm in Washington D.C., so that doesn't really help, I imagine).

What makes these toys so great, in a few words: durability, versatility, and convenience - not to mention what it does for puppy teeth!

Versatile: Flossy Chews come in all shapes and sizes- there is always one that is the perfect size for your dog, and even some that are perfect for tug of war (human vs. canine or otherwise). They don't list how to clean them on packaging, but they're incredibly durable- not to mention, FAR from expensive, so if one falls in something icky, you Can afford to replace it.

Durable: Since Lucy was little, we have struggled with one issue when it comes to toys: we have a Corgi who will sit and tear at whatever toy he gets until it is obliterated. Lucy's other toys have had to be replaced too many times- all except the tugs. These wonderful things stayed intact about a hundred times longer than other toys, and we've had to replace ONE of them (but that destruction was a joint effort).

Convenience: As I said, these come in all shapes and sizes; they have been a staple in training Lucy to control her mouth. When she was in the brat pup phase (where they get a bit mouthy), I kept a small tug on my person at all times (you can literally get ones that fit in your pocket). Whenever she'd nip, or do anything of the sort, the tug was placed in her mouth, along with a gentle but firm 'No- no bite, use your tug.'. Ditto with anything she shouldn't chew (like shoes, misc. other things you don't mean to leave out, but it only takes once..).
She now knows that when it comes to chewing, tugs are the answer. No more shoes, no more off limits items. And, no matter how annoyed she is, no matter what I'm doing, if I stick my fingers in her mouth, or take something from between her teeth, all I feel are soft spaniel lips and tongue.

Oh- and of course, the added bonus- these things actually really help teeth. The Corgi had some issues with his, but since he started playing with flossy chews, his breath is better, and his teeth are cleaner. Lucy, of course, never had a bad turn in the teeth department; dog owners who've gotten close enough have always been impressed by her pearly whites .