Okla. Stat. tit. 68, § 68-3140: Procedure to cancel deed

To defeat the deed, the person desiring to set the same aside

and recover the land, or to resist the recovery of possession by the

holder of the deed, in addition to showing clearly the entire

failure to do some one or all the things of which the tax deed is

made presumptive evidence, must show that he or the person under

whom he claims had the right to redeem the land from tax sale at the

time the deed was made, and must, when his action to set aside the

tax deed is brought, or a defense to a recovery of possession is

pleaded, tender in open court for the use of the holder of the tax

deed, all taxes, penalties, interests and costs, which the party

seeking to redeem would be bound to pay if he was then redeeming the

land from tax sale, and on failure so to do, his action or defense,

as the case may be, shall be dismissed. The rule that tax

proceedings are to be strictly construed as against the tax

purchaser, shall not apply to proceedings under this article, but in

all courts its provisions shall be liberally construed, to the end

that its provisions and all proceedings thereunder shall be

sustained.