Kidneys remove metabolic waste and harmful substances from our body by filtering about 200 liters fluid. Kidney health is as important as that of other organs, which requires great attention. For example, we need to drink enough water and do not wait until we are thirsty. According to the advice of the European Food Safety Authority (EFSA), women need to drink 2.0 liters per day and men 2.5 liters per day in a day. Drinking enough water will help to remove the toxins.
If you add 20 drops of water-soluble propolis may provide you an additional benefit by supporting your immune system. A scientific study published in 2013 evaluated the effect of propolis on symptoms of acute kidney injury in rats, including a control group. The results demonstrated the protection of propolis against renal damage by improving oxidative stress parameters.

Reference: da Costa, Marcus Felipe Bezerra, et al. "Red propolis ameliorates ischemic-reperfusion acute kidney injury." Phytomedicine 22.9 (2015): 787-795.