A Brevet can take 15 - 20 minutes, a Ring III will take 40 minutes to an hour. There is a lot more stick work during the bitework, and the stick is a baton of split bamboo, or rattan tied together to make it flair and clatter. 10 or 15 hits during an attack is fairly normal, and some decoy work includes a lot more than that. The stick is also used to intimidate the dog before he bites, and if possible, hold the dog off by using it in a threatening manner or keep the dog from rebiting if he misses or looses his initial bite. The decoy has more leeway in how they work the dogs in Ring, as long as they do not work the dogs above the level they are competing at.
Some decoys use mainly agility, some use threatening manners, etc.
Each dog is to be initially approached and worked in the same manner as all the other dogs at that level. But if the decoy sees a weakness in the dog, they are expected to exploit that weakness to their benefit, and work the dog in a manner which will exploit it as long as they are not causing physical harm to the dog. Their job is to find weaknesses, and steal points from the dog. The order of the obedience and bite exercises is drawn at random right before the dog in white comes out. The only set order is agility, obedience, bitework.