(1) Since clothes are washed in washing machine with washing powder and the fresh water is poured into iy several times till the impure water and soap come out of the clothes. Therefore, all clothes whether clean or unclean put together and washed in washing machine are clean. If there is some doubt about impurity in washing all clothes together, one should wash them separately.
(2) There is no wrong if water splashes are very little, but if there are many drops having impurity in them, then the clothes will also get impure due to those water drops. In such case, precautionary step must be taken. But yes, if the water drops do not have impure agent, then clean clothes will not get unclean on being smeared with water drops of unclean clothes.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband