The web url presents an interesting concept, but many of the concepts there aren't backed up by the scripture they are using to make their claims.
This is what the website says:
"Deuteronomy 22:20-21; Numbers 5:27 - Adulterous women loose demons of adultery on their children...
Deuteronomy 22:22-27; Leviticus 20:10 - Adulterous men loose demons of adultery on their children the same as women, along with the tendency to be cruel.
Deuteronomy 27:21 - Sex with beasts creates a very degenerate mind, physical deformities and is a form of Satan worship. Satan hates us and wants to make us lower than the animals. Some families have animal physical features. When questioned once about clubfeet, one demon said he was there because a great grandfather had sex with horses."
Here is what scripture says:
Deuteronomy 22:20-21 But if this thing be true, [and the tokens of] virginity be not found for the damsel: Then they shall bring out the damsel to the door of her father's house, and the men of her city shall stone her with stones that she die: because she hath wrought folly in Israel, to play the whore in her father's house: so shalt thou put evil away from among you.
Deuteronomy 22:22-27 If a man be found lying with a woman married to an husband, then they shall both of them die, [both] the man that lay with the woman, and the woman: so shalt thou put away evil from Israel.
If a damsel [that is] a virgin be betrothed unto an husband, and a man find her in the city, and lie with her;
Then ye shall bring them both out unto the gate of that city, and ye shall stone them with stones that they die; the damsel, because she cried not, [being] in the city; and the man, because he hath humbled his neighbour's wife: so thou shalt put away evil from among you.
But if a man find a betrothed damsel in the field, and the man force her, and lie with her: then the man only that lay with her shall die:
But unto the damsel thou shalt do nothing; [there is] in the damsel no sin [worthy] of death: for as when a man riseth against his neighbour, and slayeth him, even so [is] this matter:
For he found her in the field, [and] the betrothed damsel cried, and [there was] none to save her.
The context of these verses are not implying anything about demonic activity or "demonic curses" to the later generation of these adulterers' children and children's children. Those claims are theoretical at best.
Although I do agree that there is a spiritual warfare going on in which we can not see, I think most of the time we are dealing with our our own flesh, our own sin nature. And because of this we must know the enemy--the enemy within.
This is what Puritan writer John Owen said, "[Since] there is such a law [of indwelling sin] in Christians, then it is our duty to find it out, as if a fire were in our home. Our earnestness for grace, our watchfulness, and our diligent obedience depends upon this discovery. Upon this one hinge the whole course of our lives will turn. Ignorance of it breeds senselessness, carelessness, sloth, self-sufficiency, and pride--all of which the Lord's soul abhors."
Paul said in Romans 7:18, "For I know that in me (that is, in my flesh,) dwelleth no good thing; for to will [to do right] is present with me; but how to perform that which is good I find not."
So we should as Proverbs 4:23 says, "Keep [watch over; guard] thy heart with all diligence for out of it are the issues of life."
Jim Berg in the book Changed In His Image
gives this good illustration: "When we take a tea bag, place it in a teacup, and fill the cup with hot water, the water activates the tea in the bag, unleashing its taste into the water around it. The hot water didn't create the taste; it merely revealed, or drew out, what was already in the bag. This depicts what happens in the human heart. The pressures around us . . . merely draw out of our heart what is already in it."
Walk in the Spirit
Not in the flesh!