[Rav Aryeh Lebovitz in his shiur at around 6'58''](http://www.yutorah.org/lectures/lecture.cfm/744040/Rabbi_Aryeh_Lebowitz/Ten_Minute_Halacha_-_Washing_for_Davening) quotes authorities that do not require washing with a vessel (keli) for washing before praying. 
(I do not have the sefer he quotes. )

Who are these authorities?

Closely related https://judaism.stackexchange.com/questions/35272/washing-before-davening-1-or-3-times