Rue can be extracted incredibly quick. With longer extractions, you pull more of the nasties out. I would suggest roasting the seeds lightly in a pan. This makes it easier to pulverize, and the taste is better.For eg - Soak 2 - 3 g pulverized Syrian rue seed in lemon juice (50ml) and water (150ml) for 8 hours. Then strain/filter well to get 200 ml of bright, clear yellow extract. Drink this mixed into a tall glass (300 ml) of OJ...
Then powder it in a coffee grinder. After this, put it in a jar, with 200-400 ml water, and some vinegar. Shake it. Then quickly filter it. The water used, should be no more than room temperature, to avoid pulling out nasties. Besides, it makes it easier to filter. Then reduce. Should make for a more palatable brew.
Alternatively, you could use a plastic bottle, cut of the bottom, then stuff some cotton in the top opening. Then put the rue powder on top of that, then some more cotton, or something to keep the powder from floating up. Then add water and let it sift through the rue powder and into the jar.
If you find that the filtered brew is not clear, you may use an egg white to clean out the particles.