Many thanks for your reply! So when used milui v’irui? Toda’.
Shalom, The form of koshering you refer to - milui v'irui - is done by soaking the items for three days in water, changing the water after every 24 hours. This method of koshering is used when koshering vessels used to store non-kosher wine for longer periods (see Shulchan Aruch Y.D. 137). The law differs depending on the material of the casket, and the length of time the non-kosher wine was in it. It is also used, in times of need, for Ashkanazim to kosher glassware for Passover. This also depends on how the glassware was used - hot or cold etc - and the urgency of koshering it as opposed to the preferable option of using new items. Blessings, D. Sperling.