Is the basin used for istinja' considered impure after istinja', and what is the ruling on the purity of the water splattered from it onto clothes during wudu'?

Pouring water on the spot after urination does not leave impurity in a regular basin where water does not settle. One wash is sufficient due to the lightness of the impurity and the abundance of water. Water splashed during ablution is pure. It is not necessary to pour water on the basin after purification with water (istinja') if no istinja' water remains in it, though if done as a precaution, there is no harm. One must beware of obsessive doubts (waswasah).