Kavod HaRav, Is there ruach ra remaining on dried water? For example if the water with ruach ra soaked into a stack of papers, and the papers dried, is there any way to get the ruach ra out of it?

Shalom uvracha, I assume that what you were referring to is water from the morning ‘netilat yadaim’ (ritual washing) or ‘maim achronim’ (washing after the meal). There is a 'ruach ra'ah' (bad spirit) in water of 'netilat yadaim' in the morning (Shulchan Aruch, 4;8), and also in 'maim achronim' (Shulchan Aruch, 180;2). Therefore, the Shulchan Aruch ruled that one should not perform netilat yadaim which may spill onto the ground because it might cause damage to someone who walks there. However once the water is dry there is no Ruach ra'ah anymore. (Magen Avraham 181; 2 regarding 'maim achronim' and Piskei Teshuvot 4;147 regarding water from the morning 'netilat yadim') By the way, one may do 'netilat yadayim', wash his hands, inside a sink, even with dishes in it. This presumes that the dishes will be washed soon afterwards (Rav Avigdor Neventhal in 'Beyitzchak Yikare', 4, 8). All the best,