Impurities

Removing impurity from a touch screen phone

Q: I have a question regarding impurity and touch screen phones. I would like to know how invisible impurity such as urine traces or other invisible impurity may be removed from a cellphone as it cannot be washed as it would be ruined. Would wiping the dry invisible impurity with a dry cloth remove it from the smooth surface of a phone? Or how about a wet cloth that is wetted with isopropyl alcohol (as this does not harm the phone)?

Living in a place where there are dogs

Q: I have got the scholarship for further studies abroad. I pray fives times a day.

1. The country I am going to, they eat pork and dog meat. This scholarship will be a life changing opportunity for me but I am worried that I need to interact with the local people on a daily basis, like professors and other classmates. Anything haraam I should avoid while interacting with them like hand shake or exchanging things?

2. I need to rent a room. They normally keep dogs as pets in their houses and fridges are also available in the rented houses in which they keep dog meat and pork. Should I use this fridge, stove and how to clean (purify) this place for living here if they kept dog meat in there?

3. I will offer prayer in that room. Explain briefly about the najasat of dogs and their saliva because dogs are everywhere in this country. They are in public places and sitting onbenches that are basically for humans to sit on.