According to the Torah (see Sefer Vayikra 6:20-21), in the context of discussing a korban hatat – a sin-offering – “Whatsoever shall touch the flesh thereof shall be holy; and when there is sprinkled of the blood upon any garment, thou shalt wash that whereon it was sprinkled in a holy place. But the earthen vessel wherein it is cooked shall be broken; and if it be cooked in a brazen vessel, it shall be scoured, and rinsed in water.”
Thus, if sacrificial blood is absorbed by another object, the laws pertaining to the sacrifice are transferred to the object unless the blood is removed. Specifically, clothing that was stained by blood had to be washed in the Temple courtyard, metal vessels that absorbed blood could be heated until the blood is removed, but earthenware vessels, which retain anything that they absorb, must be destroyed.
Our Gemara quotes a Mishnah that teaches that this law is limited to blood that could be sprinkled on the altar. Thus, if the korban was disqualified for some reason – whether the sacrifice was never a good one or if there was a moment that the sacrifice was good but then it was disqualified – the blood need not be cleaned. Examples of a good sacrifice that was disqualified include situations when the meat of the sacrifice was left over after the appropriate time, if it became ritually defiled or if it was removed from the Temple precincts. Examples of sacrifices that were never good are situations where the korban was slaughtered in the wrong time or place, if the blood had been collected by someone who was unfit to participate in the sacrificial service (see Massekhet Zevahim daf, or page, 15). In such cases the blood would not need to be cleaned from the priestly clothing.