Removing impurities

Q: When a person has a wet dream or masturbates, he spreads impurity! When he spreads it, it (sperms) touches the furniture, the furniture is impure right?

1. How to clean the furniture (sofa)

2. How to do ghusal?

Taweez

Q:

1. I would like to know about the taweez, some taweezes are written in numbers. So what have numbers to do with taweez or naqash?

2. As discussing worldly things in the Masjid is not allowed, so what about if someone put his visit cards of his business in the Musjid to get customers?

3. Does dua make and effect on our destiny. If something is written in our destiny, can dua can change it or not?