Dry siphon - permanently prevent channel odors
If a siphon is not used for a long time, it will dry out and it will smell like a canal. Reinfilling water helps - but that soon evaporates again.
Just mix water with a dash of cooking oil. Shake well in an old canister and immediately fill in the siphon. In the siphon, the mixture separates again, the oil rises and closes both legs of the siphon airtight. The water can no longer evaporate, the odor trap is maintained until someone takes in water.
Oil has usually lost nothing in the sewers. But edible oil is biodegradable and over salad dressings, etc., which we throw away every day, so also comes a lot of oil in the sewer. So I think that's justifiable.
Mixing ratio: so much water that the siphon is safely filled. So much oil that creates a 1-mm layer of oil. I guess, 5-10% cooking oil would have to fit.
Try it, the siphon is already tight for a few months.
