The reason as brought by the Ran and the secondary opinion in the Mordechai is to soften the meat in order to allow for easy removal of the blood by the salt. The Mordechai writes that the reason is in order to remove any dirt which may be on the meat because otherwise the salt will simply fill up with blood and not do its job of removing the blood. The Hagos Maimoni is of the opinion that it is to remove the blood that is on the surface of the meat, for otherwise the salt will simply fill up with it and not perform its job of removing the blood that is inside the meat.
 This is of course if the butcher performed a thorough rinsing as is required, such as by soaking the meat in a vessel. If so, then you need not wash it at home. However, a mere spraying is not acceptable even post facto. If we know the butcher rinsed the meat, we can assume it was done properly.
 Only if cut with a knife will you have to go back and re-wash, because through the pressure of a knife, blood is brought up to the surface. However, according to the Ran who holds the reason for the washing is to soften the meat, it would make no difference how many cuts are made, and re-washing would not be required. However, halacha follows the opinion that the rinsing is due to blood, therefore re-washing will be required even post facto.
 Re-washing is required only if the hooves were sliced off, however if they were not cut, they are as any other part of the meat, and no special washing is required.
 However a small rinsing is insufficient, and one is required to go back and properly rinse the meat. However if the meat has already been salted after such a small rinsing, it is acceptable post facto.
 However do not let the meat completely dry for then the salt will not stick to the meat or melt at ail.
 According to the halacha it would be permissible to use the vessel with other things, because the vessel doesn’t absorb anything since the meat does not soak for twenty four hours, and it is used for cold items. However we customarily refrain from doing so due to blood that might be stuck to the vessel.
 This is due to the rule that something soaked for twenty four hours, is as if it was cooked. (Kavush K’mevushal)
 Later it is explained that it is even forbidden to roast this meat. If there was a sixty ratio of water against the meat, it may even be cooked.
 The reason we permit it is because the second meat will not be in the vessel for a twenty four hour period. Even if it was soaked for twenty four hours, any taste released will be a stale one thereby not causing the meat to be forbidden.
 The Maharshal writes that meat that was frozen may not be salted until it is defrosted. Meat that was salted but frozen before the end of the required salting period should be re-salted when it melts. If it wasn’t re-salted but it did undergo the required salting time after having thawed and it was subsequently cooked - it is permitted, post facto.