Well, first I would look into the more mundane explanations, such as the ones that have already been suggested. It could be nothing more than the types of vermin that are common in that area… if you have rats or mice running around, that would be a good explanation for the urine. It could be bugs. It could just be a plain old string of bad luck – “stuff” happens, haha!
In Louisiana, both Hoodoo and Voodoo are traditional magical practices in that part of the country, with their own unique traditions that differ from other parts of the south. I know that urine is a common ingredient used in Hoodoo spells, but it’s usually human urine that’s used, and it’s used for entirely different purposes. It can be used in love spells, and (if someone can get some of your own urine, which is pretty difficult nowadays) it can be used to curse you. There’s also a Hoodoo tradition of urinating along a knife blade and letting it run onto the ground to render someone impotent, but again, that would be human urine, not rodent urine. Of course there might be many other ways of using it, so who knows… But to me, it sounds like there could be perfectly logical explanations for what’s going on.
From what you described of your mother-in-law, it doesn’t sound like what she’s practicing is magic or witchcraft in any way. It’s important to differentiate between New Age practices (of which there are many) and witchcraft (which also takes many different forms). Her practices sound more about inner work (self-empowerment and psychology) than casting spells. I’m not quite sure what you meant by “youngean philosophy” – did you mean Jungian psychology? If so, that’s just a branch of psychology, also called depth psychology, and doesn’t really have anything to do with New Age beliefs. It’s just a form of psychoanalysis.
If you truly believe that you, your family, or your property is cursed, the first thing I’d recommend is to have priest over to bless your house. If there are any particular objects you’ve found on your property that you believe are from spells, remove them from the property immediately. You could also use some blessed St. Benedict medals, which require a special blessing from a priest, to get rid of any demonic forces that might be involved. They’re a powerful sacramental with exorcising properties, but they have their own particular blessing that’s a bit different from blessing any other medal. It’s traditional for Catholics to bury four blessed St. Benedict medals on their property, one at each of the four corners of the property. Any priest can bless them, and you can find the blessing rite here, if your priest doesn’t have it in his book of blessings:
fisheaters.com/stbenedictmedal.html
In addition to the house blessing and medals, don’t hesitate to invoke the aid of St. Michael the Archangel! The Prayer to St. Michael (“St. Michael the Archangel, defend us in battle…”) is a great one most everyone knows. The Chaplet of St. Michael is also a great prayer, and the Archangel has promised that anyone who prays it will receive the aid of the angels throughout their life. Also, keep holy water in your home, bless yourself with it frequently, and have your family do the same. As many saints have said, both holy water and the Sign of the Cross make devils flee! A good prayer while doing this, favored by St. Benedict, is: “By the Sign of the Cross, deliver us from our enemies, O Lord.”
Of course the most powerful protection you could possibly get is by calling on the holy name of Christ.
I’m not suggesting any of these things out of superstition… they’re simply practices and sacramentals that Catholics throughout history have used. I’d still wager that there are mundane explanations for all of this, but if you think your mother-in-law has reason to be using magic against you, and it really seems witchcraft is the only explanation – by all means, use the intercession of the saints, the power of Christ, and holy objects to protect yourself and your family.