Edit: per above comment, see here: Is Leviticus 14 describing a cure for leprosy?
14 And the Lord said to Moses,
2 This shall be the law of the leper on the day when he is to be
pronounced clean: he shall be brought to the priest [at a meeting
place outside the camp];
3 The priest shall go out of the camp [to meet him]; and [he] shall
examine him, and if the disease is healed in the leper,
4 Then the priest shall command to take for him who is to be cleansed
two living clean birds and cedar wood and scarlet [material] and
5 And the priest shall command to kill one of the birds in an earthen
vessel over fresh, running water.
6 As for the living bird, he shall take it, the cedar wood, and the
scarlet [material], and the hyssop, and shall dip them and the living
bird in the blood of the bird killed over the running water;
7 And he shall sprinkle [the blood] on him who is to be cleansed from
the leprosy seven times and shall pronounce him clean, and shall let
go the living bird into the open field.
This very likely has nothing to do with literal sanitation, but like many things of the law, its a reflection of heavenly things, heavenly benefits, and quite often the things involved are symbolisms * although the people of their day took it literal.
Looking at verse 2-3 it appears this is a ritual upon being pronounced clean - not on the cleansing itself.
The law is a reflection of heavenly things:
5 [But these offer] service [merely] as a pattern and as a
foreshadowing of [what has its true existence and reality in] the
heavenly sanctuary. For when Moses was about to erect the tabernacle,
he was warned by God, saying, See to it that you make it all [exactly]
according to the copy (the model) which was shown to you on the