What can happen is that if you have them vomit the wrong thing, it can cause more damage coming up than it has the potential to do just going straight through. Underwear could have fallen into that category if the elastic jammed somewhere, or as you say the dog could have gone into distress, inhaled vomit, and then you'd have a real emergency situation.
So you were right to call the vet. And you didn't waste your money taking your dog in. You had the best possible outcome (well, other than your dog immediately upchucking the undies right away so you didn't worry at all), but there were many scenarios that would have required the vet's intervention.
The receptionist has to describe the worst possible scenario, so you are prepared. Like when I brought Lynn to the vet with all the signs of parvo. They showed me a quote that included two weeks of specialized hospital care (they don't charge over that, no matter how long the dog is there), all the meds she might need, and one parvo test. I added a parvo test when the first was negative (that one was negative too), but other than that I knew what the worst could be - about $1100. It turned out to be only $550 and she was out in four days, thank goodness. But imagine if the vet didn't prepare someone for the worst case scenario.
There are many times that it's fine to administer an emetic at home (if you don't have peroxide, salt on the back of the tongue works too). But unless you have prior experience with the exact circumstances, call your vet or poison control first. Zhi loves raisins but they are poisonous to dogs! I've had to make her upchuck raisins and grapes so many times that she goes running when I get the salt out while cooking. So in that case I know what to do.
But, another time I had a dog eat 100 tablets of vitamin B. Upchuck, yes or no? The answer was no! B is very irritating and the vet didn't want to risk damage to the esophogus. B is water soluble and gone from the body in hours, and tolerable up to levels of thousands of times over the recommended daily allowance. So she simply had me give him plenty to drink and watch him carefully.
Becca Shouse
Maggie and Zhi (queen bees), Ben, Gus, Cord, Rocky, Ted (BCs), Lu and Tully (Maremma flock guardians)
"Protect, Herd, Love" Irena Farm, Semora, NC
"We didn't have a phone, and we couldn't call you!" Helen, AIDS orphan. Don't let them die of ignorance - WorldHelp.net
"I-Dog Biggest Loser" Official Cheerleader/Mascot
Start 09/15/08: 186.4 lbs Current 185.5 lbs