Before you start pouring random products into the toilet, it helps to know what problem you are actually trying to solve. A lot of toilet stains are caused by limescale. This is the chalky buildup left behind when water evaporates or sits in the bowl for a long time. Once dirt sticks to that rough layer, the toilet can look older and dirtier than it really is.
This is where vinegar comes in. Vinegar is acidic, which makes it useful against limescale. It does not replace proper cleaning forever, and it will not fix every stain in every toilet, but it can make mineral buildup much easier to remove. The key is contact time. If vinegar runs straight into the water and disappears, it has very little chance to help. That is why simply splashing some in the bowl often disappoints people.
The cloth method solves that problem. A vinegar-soaked cloth can sit directly against the stained area. Instead of sliding away, the vinegar stays where you need it: on the ring, patch, or line you want to clean. It turns a quick rinse into a targeted treatment that can save a surprising amount of effort later in the week.