A mouthful of seawater is not needed to recognise the ocean’s saltiness. The more interesting question is how dissolved material became part of that water in the first place.
Follow material into the ocean
NOAA’s explanation of ocean salt identifies weathered rocks on land and seafloor openings among the sources. Water moving through the landscape transports dissolved material; processes beneath the sea contribute to the chemical story as well.
Separate origin from concentration
Where salts come from is a different question from why salinity varies between places. Evaporation, rainfall and freshwater input can change local concentration without being the original source of every dissolved ion. Keep those two explanations on separate lines in a study note.
Try drawing a simple diagram with arrows for material entering and a second set for water moving or changing phase. Label it as a simplified model. It should help you ask better questions, not imply that the ocean is a sealed bowl whose chemistry can be explained by one river and one process.