Commentary for Avodah Zarah 149:8

If one wants to purify them quickly without waiting twelve months or a similar length of time there are two opinions as to what to do. One is that one can pour boiling water (or olive- water) over them. Alternatively, he can put them in a rapidly moving stream of water. The Talmud says he puts them in the water for an “onah.” In tomorrow’s section we will learn how long an “onah” is.