Guaranteed to work, as these instructions are from the mouth of God and available for your perusal in his Inerrant Word:
“11And the LORD said to Moses, 12“Say to the people of Israel: `Suppose a man’s wife goes astray and is unfaithful to her husband. 13Suppose she sleeps with another man, but there is no witness since she was not caught in the act. 14If her husband becomes jealous and suspicious of his wife, even if she has not defiled herself, 15the husband must bring his wife to the priest with an offering of two quarts[b] of barley flour to be presented on her behalf. Do not mix it with olive oil or frankincense, for it is a jealousy offering–an offering of inquiry to find out if she is guilty.
16” `The priest must then present her before the LORD. 17He must take some holy water in a clay jar and mix it with dust from the Tabernacle floor. 18When he has presented her before the LORD, he must unbind her hair and place the offering of inquiry–the jealousy offering–in her hands to determine whether or not her husband’s suspicions are justified. The priest will stand before her, holding the jar of bitter water that brings a curse to those who are guilty. 19The priest will put the woman under oath and say to her, “If no other man has slept with you, and you have not defiled yourself by being unfaithful, may you be immune from the effects of this bitter water that causes the curse. 20But if you have gone astray while under your husband’s authority and defiled yourself by sleeping with another man”– 21at this point the priest must put the woman under this oath–”then may the people see that the LORD’s curse is upon you when he makes you infertile.[c] 22Now may this water that brings the curse enter your body and make you infertile.[d]” And the woman will be required to say, “Yes, let it be so.” 23Then the priest will write these curses on a piece of leather and wash them off into the bitter water. 24He will then make the woman drink the bitter water, so it may bring on the curse and cause bitter suffering in cases of guilt.
25” `Then the priest will take the jealousy offering from the woman’s hand, lift it up before the LORD, and carry it to the altar. 26He will take a handful as a token portion and burn it on the altar. Then he will require the woman to drink the water. 27If she has defiled herself by being unfaithful to her husband, the water that brings the curse will cause bitter suffering. She will become infertile,[e] and her name will become a curse word among her people. 28But if she has not defiled herself and is pure, she will be unharmed and will still be able to have children.
29” `This is the ritual law for dealing with jealousy. If a woman defiles herself by being unfaithful to her husband, 30or if a man is overcome with jealousy and suspicion that his wife has been unfaithful, the husband must present his wife before the LORD, and the priest will apply this entire ritual law to her. 31The husband will be innocent of any guilt in this matter, but his wife will be held accountable for her sin.’ ”
~ Numbers 5:11-31 (New Living Translation).
Bet you didn’t know there was a fool proof method to determine whether or not your wife was cheating on you, huh? I suppose in this day and age, where many people don’t have access to barley flour, religions with priests could possibly accept money as an offering or payment for this test. The money though would have to be tainted in such a way so that it can be shown to be a “jealosy offering.”
Ah, better yet, let them buy barley at the local bulk food store, and grind it into flour. As far as “holy water,” I imagine Roman Catholic priests will have access to this. I guess the only thing to wonder about is whether the dust from the Chapel will work as well as the dust from the Tabernacle.
But you can always try. The inerrant word of God says it will work.
A married couple that did not want to have children could always use to their own advantage as well. Let the husband send off the wife, where she has sex with another man, but there is no other witness. Let the husband then take the wife to the priest and have the test administered. As His Word says, she will then be unable to have any children in the future.
I wonder what would happen if your wife was bi-sexual though. Hmmmm.