Well, Mythbusters did an experiment, and in that particular case, the dog had a cleaner tongue.

http://mythbustersresults.com/

i realy dont know soz

When used properly, tongue scrapers can remove bacteria and dead cells from your tongue's surface. However, if you use a tongue cleaner too much or too aggressively, it can damage your taste buds.

You will have good breath and a healthy tongue. You're supposed to brush your tongue and rinse your mouth with mouthwash when you brush your teeth.

yes ! it always has been and always will :)