Even after the vessel has been washed.
 This is referring to a case where the dish was cold, and a boiling hot item was placed upon it making both considered to be 'cold' because of the rule of tatai gavar. even so one must take a klipah, even if it is dry.
 As a general rule, we assume that the food in a vessel is sixty times that of its klipah, therefore why is the Rema stating this law here? Rather, this is the general rule with regards to most vessels, however, a vessel that is very wide and not high might not have sixty.
 An earthenware vessel may not be initially used without being washed off. Other vessels, however, are permitted as long as they are at least wiped down before use.
 This is because salting can not bring out the taste from a vessel. Why then did the Rema write this here after the some say’? This is because one will probably wash off the meat before cooking it. One may even place it on a non-kosher vessel. However with other things, even if cold, it is forbidden to use this vessel for one might forget to rinse it off.
 For example, salting for preservation, in which the meat is often left in the salt for longer than 24 hours, is permitted because the salting does not bring out taste from vessels. Even if taste would come out after the 24 hours of salting, it would be considered nosen taam lifgam. Ideally meat should not be left in such a vessel, because nosen taam lifgam is initially forbidden.