When visiting someone who doesn’t keep kosher, or renting an airbnb that comes with pots, pans, etc utenisils, can you use those utensils without kashering? Since they aren’t mine, can I just use aino Ben Yomo and from there on keep the ones I use for milk and the ones I use for meat sperate for myself for the rest of my visit?
No. You must still kasher the metal and not use any unglazed ceramic. Glass does not need to be kashered.
If eno ben yomo why can’t I use spoon for yogurt etc?
The Halacha says that we must treat eino ben yomo like Ben Yomo.