Answered by Shaykh Faraz Rabbani
If someone has dried urine on his hand (no moisture), do the things he touches with the impure hand also becomes impure (like clothing)?
Answer:
Walaikum assalam wa rahmatullah,
I pray this finds you in the best of health and spirits.
Touching dry with with a dry (or moist) hand is not considered to transfer the filth, unless the traces of the filth (color or smell) appear on the hand. [ Shurunbulali, Maraqi al-Falah ]
And Allah alone gives success.
Faraz Rabbani