If a fleishig dish was by mistake cleaned in the milchig kitchen(or vice-versa) how to make it kosher again? If I remembered correctly my grandmother for the old continent told me they could be buried for a period of time and then voila they were kosher again…It there any opinion favoring this behavior? If so when is this possible or who accepts this view?
I personally haven’t found anything on the subject, but that doesn’t mean that it isn’t a valid minhag. There are many minhagim that have very good reason, but unfortunately over time we no longer know the reason for them.
It is possible that it may have to do with the following idea. There are certain vessels that cannot be kashered, such as porcelain, pottery etc. however there is an opinion that if the vessel stays without anything inside of it for a full year, that whatever absorbed taste inside it already dried up and is like sand and the utensil is not permitted to use.
This opinion is not widely accepted as norm, however coupled with other factors we can rely on it.
Regarding the fleishig dish that was washed in a milchig sink, it depends on a number of factors, if there were dirty meat dishes in the sink at the time, if the water used would be considered irui kli rishon or kli sheini, if detergents were used, etc.
Sharei Teshuva Siman 451-1 in the name of Chacham Tzvi, Aruch Hashulchan 451-2, Igros Moshe Y”D 2-46.