After using the bathroom, is one allowed to say asher yatzar without drying the hands, then wash for netilas yadaim?
There are different opinions about this. There reason why some people dry their hands is the following. There is a concept in Hilchos Netilas Yodayim that if one touches water that is tameh, that even when he pours tahor water over them, the water becomes tameh. The opinion of the Mishna Berura is that if one pours a revi’is of water over his hand at one time, (of even in two times) that it is purifies the water. Therefore the Mishna Berurah says that one should be careful to pour a full revi’is over each hand in order to avoid this and other issues. Other (the Gra”z and Chazon Ish) however are stricter about this, and say that any water that is tameh in relation to netilas yodayim, will impurity the water. This is why some people dry off the handles of the washing cup before washing with it. Washing one’s hands after the bathroom would create the same issue, therefore many people wipe their hands off between the two washings, (especially because now the person’s hands are tameh from washing related water). However technically according to the Mishna Berura, if you are careful to wash both hands with more than a revi’is, it would not be necessary.