high percentage of midwestern sportsmen got into the field trial game because they saw it as a means of polishing the performance of their duck and pheasant dogs and keeping them in shape during the off-season. Tests were simple then as compared to today, when trials display the epitome in obedience training. But they were also fussier about a lot of other things like "line manners" and, you guessed it, "hard mouth." Most judges examine every bird retrieved for any signs of this serious fault.
So, out of necessity, I had to give serious thought to correcting Clinker's problem. The idea of making it unpleasant for the dog when it crunched down on a bird or dummy seemed reasonable to me. But I needed a better training device. We had scrub brushes in the quonset hut that served as student housing for veterans. We had two dogs living in the house. From time to time, being strong "natural retrievers" they'd pick up a scrub brush and bring it to me. They'd also fetch it, gently, when I threw it for them, Eureka! Drill this hardmouthed Lab pup with a scrub-brush "dummy" until she got the idea that anything she was sent to fetch could be grasped firmly with respect.
Clinker went on to retrieve to hand over the next eleven years game birds of various sizes and shapes, hunting and field trialing. She delivered still-living "crips" on many occasions. But it was her practice to "take no prisoners" and some birds, while fit for the table, were marred; circumstances for this being explainable. Recognizing some of the realities of hunting situations and field performance by working gun dogs leads to making excuses for various causes.
Scrub brush dummies aren't a guaranteed miracle cure for hard mouth. No tool or procedure will work with every dog. But since I have used them subsequently to salvage some retrievers that might otherwise be undesirable, I'm not blowing smoke.
If you have a pup with a "mouth problem" a scrub brush may clean it up. No harm will be done trying it, even if you discover that your suspected perpetrator isn't guilty of that crime. Quite a few dogs are labeled "hard-mouth" but don't deserve to be maligned. But this elementary training technique should at least be known by all retriever trainers.

Dave Duffey hails from Bowler, WI