Hilchos Issurei Mizbeiach 6:5

The previous halacha (about not redeeming flour, wine, oil, etc.) applies when they were rendered unfit or ritually unclean after being sanctified in a service vessel; before being sanctified in a service vessel, they may be redeemed if rendered unfit or ritually unclean. Ritually clean things may not be redeemed even if not consecrated in a service utensil except for flour brought as a sin offering. Regarding this, Leviticus 5:6 says, “from his sin-offering” and verse 13 says, “on his sin offering.” We derive that one may bring a sin offering from the money of his sin offering. [We will see IY”H in Hilchos Shegagos that this refers to a needy person who bought a flour offering and subsequently became well-off financially. In such a case, he may sell the flour designated for the offering and use the money to upgrade to an animal offering.] Accordingly, before being consecrated in a service vessel, it is considered consecrated for its value. Therefore, it can be redeemed even in a ritually clean state. A separate woodpile was made for the accoutrements of offerings that were rendered ritually unclean. These were burned on the altar.

Hilchos Issurei Mizbeiach 6:6

The Rambam now discusses water for the Succos libations that was rendered ritually unclean and then connected to a mikvah and purified. (This scenario will be discussed further IY”H when we get to laws of ritual purity and impurity.) If the water was purified and then consecrated, it may be used for libations. If it was consecrated and then rendered unclean, since it was removed, it remains removed.