"Two squeakies" is a skill building game that I've played with all my puppies for several years now. The "two hoses" exercise was first introduced in Gottfried Dildei's book, Training for Drive. In a nutshell, you stand holding the two hoses (about one foot of garden or radiator hose) and toss one hose thataway. The dog chases the hose. When the dog returns with that hose, you toss the other hose the opposite direction, in a linear fashion.
The point of the exercise is to build drive for the retrieve and eventually to introduce the concept of the aus (out) on command. The dog first learns that if he retrieves the hose and brings it back, he is rewarded with a toss of the (other) hose. Subsequently, you can introduce the aus. The dog learns that if he outs the first hose on command, he is rewarded with a toss of the other.
I achieve better focus with puppies by using squeaky toys for this game. I first introduce the game in a short hallway inside the house. In this fashion, the pup has a limited area within which to run after the squeaky, and little option but to come back up the hallway toward me. This helps build the natural progression to run, retrieve the toy, return it to me, and release it for the next toss.
Note that this game involves many distinct behaviors -- noticing the toy, running after it, investigating it, picking it up, running back with it, dropping it. At each step in the pup's developing understanding of the game, never underestimate the importance of praise, praise, PRAISE! You're playing, you're excited and enthusiastic, cheering your pup on, congratulating him for each new achievement. We're having some fun now! Major canine cerebral turn-on!
Once we have the basics down, I toss the second toy a short distance in the opposite direction (behind me).
The puppy quickly learns that this is a two-directional game. With daily repetition of the game, in very little time you can progress from a single, short toss down the hallway indoors to tosses of 20 feet and beyond in both directions out of doors.
As the dog matures and develops, you can introduce a variety of other skills using this game. Platz for reward, sit for reward, fuss -- anything really. Once you've developed the dog's focus on the hose in a controlled "play" environment, you can incorporate a variety of skill-building activities into the game. The dog develops a love affair with the hose that can be effectively used during later obedience training on the field. A hose may be easily tucked under the armpit (the Garden of Earthy Delights Hose), hidden in a pocket (the Pocket Snake), tucked into your waist band (the Panty Hose), or held parallel to the forearm (the Meat Grinder), and quickly produced for well-timed reward/play purposes.
Some dogs quickly learn to anticipate the second hose and drop the first hose too early. After all, he seeks the reward -- the second hose. You then apply motivational direction to the game. You withhold the reward (the hose) until the dog is performing the behavior you want -- in this case, you want the dog to drop the hose right at your feet as he's running past you toward the anticipated landing spot of the other hose. (Some folks will train the dog to drop the hose into the hand.)
You gradually increase the pressure on the dog to drop the toy only when and where you command. This takes a certain amount of time and patience and is influenced by the temperament, drive, and trainability of the dog. By withholding the reward until the desired behavior is performed, the dog quickly learns to isolate the correct behavior ("Ah! When I do this, I get the hose!") and will voluntarily perform that behavior for the reward. It's really no different than training to refine any other behavior/skill.
For example, in the typical "sit" exercise, the desired goal is to have the dog sit "perfectly" next to you -- not head in, butt out, or any derivation thereof. When you first train for the sit in a pup, you reward the first variations of a sit, without insisting on "perfection." Then, once the pup understands the basic "sit" command, you can continue to motivate the dog, through appropriately timed rewards (toy, food, aural or tactile praise), to assume the desired "perfect" sit position.
Same with two hoses. You continue to escalate the motivational pressure to perform "perfectly" by further delaying the release of the second hose until the dog has retrieved the first hose and released it in the exact manner you demand. However, your demands must be reasonable and must be within the framework of the dog's level of understanding of the task. You will only frustrate the dog (and the trainer) if you expect the dog to understand the subtleties of this game after only one or two renditions, or if you attempt to escalate your demands for sophisticated precision before the dog has a firm understanding of the rudimentary basics. Remember: this is a game. Keep it fun! (The theme of "baby steps" in the film What About Bob? is an appropriate one for our purposes here.)
There is an oft-used expression, "Perfect practice makes perfect." Keep in mind that "perfect practice" can only occur after (1) you have established a sound foundation (the dog understands the required task); (2) you have proofed the task to verify its soundness (and if it's not sound, you return to the basic foundation work); and (3) you exercise correction if -- after the dog clearly understand the required task -- the dog fails to perform it correctly. It's a process that occurs over time (repetition). Embedded in the framework of that time continuum is the process of exercising perfect timing at each instance.
I haven't met a dog yet who didn't love the game! When the dog is having all that riotous fun playing two hoses, it's only you who appreciates all the focused training and precision that is going into the "game." Once the strong foundation has been laid, you can vary the game to re-ignite the learning process and introduce new tasks.