Chooco:
No you shouldn't really rub thier nose in it. Would you rub your kids nose in a puddle of piss if he accidentally wet the bed? I hope not......
What i do is hold them by the collar and take them to the spot, I then point at the spot and tell them NO! in a firm authoritative manner. Then you immediately take them outside. They won't get it the first few times, but they will eventually. There are ways of house training dogs and puppies, but It's long and detailed so I won't burden anyone with it now. Keep in mind that dogs are not as dumb as people think they are. Most dogs that "go" on the carpet have a good reason.... They are stressed, need attention, not properly trained, sick, no one is home to let them out. As a dog gets older, he learns to hold it longer. Puppies should be taken out as soon as they eat. With most dogs it's food in-food out. Take this into account when owning a house dog.