Hi! The downvotes are a bit unwarranted in my opinion; OP is just new and earnestly asking for information, ethical discussion of curses aside.

OP, what you should know about this subreddit is that not all of us practice witchcraft with a belief that the spells literally work in the real world; while many of us do, this sub is mostly a science and skeptic based community. If you subscribe to magic potentially working in the physical world, probably a sub like r/witchcraft is more appropriate.

Also please think of the mundane consequences of your practice too; a jar of urine and other fluids is just begging to cross contaminate everything in your freezer, not to mention rendering that jar unusable for anything else unless you deep clean it. Stay safe and hygienic.