May one wash negel vasser over dishes in the sink?
One should be careful not to wash negel vasser over dishes in the sink, because they will have to be washed (once) afterwards. If someone knows that whatever is in the sink will be washed then there is no concern about it.
Halichos Shlomo (Teffilah) 20 ftnt .11, Eishei Yisroel 2 ftnt. 72.