A tray of baked turkey came out of the oven and then a sizeable amount of the turkey sauce spilled directly onto a milchig sandwich toaster (known in Israel as a “טוסטר לחיצה”). This is a toaster used to make what Israelis call “toast” meaning you put in it bread with cheese and close the top to cook it. The toaster was not very clean, as they are hard to clean. I do not know when it was last used for milchigs, but it was cold.
The fleishig sauce spilled from a kli rishon a few seconds after it came out of the oven, so it was boiling hot.
How must the toaster now be kashered?
If the sauce spilled on the outside of the toaster you should just wipe it off and awash it well and you can still use it. This is because the fleishig sauce was only iruy kli rishon, which would only get absorbed a little bit on the surface that it hit, which on the outside of the toaster and won’t come in contact with the cheese or food inside it.
If however the sauce spilled on to the inside of the toaster then we say that only the actual place that the sauce spilled became treif and needs to be kashered, however we would only have to do iruy kli rishon to it. Therefore wait ubntil 24 hours after the sauce spilled, the part that was spilled on would have to be cleaned well, then pour boiling water over that area.
Shulchan Aruch 451-5