When i used to work in a currency exchange during initial training we were always advised to wash our hands after handling certian currencies. India, Gambia and Egypt were 3. The Egyptian stuff was the best, one day we had a guy in full arab dress come in to change US Dollars into Sterling he reached under his robes and pulled out a stack of warm, damp $100 bills. It was then i worked out where they came from as his robes didnt have any pockets!!!