In El Cajon, plenty of the houses are older, and their drains have carried everything a household produces the whole time. So when your drain clogs, gets snaked, and clogs again a few months later, understand what actually happened. The snake opened a hole through the blockage, but the decades of grease, soap, and buildup lining the pipe stayed right where they were, and they close the gap again over time.
Hydro jetting deals with the actual problem. A high pressure water stream scrubs the pipe walls clean the whole way down the line. It strips the buildup off instead of tunneling through it. For an older El Cajon drain that's been opened up a few times but never actually cleaned, that's the first real cleaning it's had.
That said, not every drain needs it. Sometimes a snake genuinely solves it. The contractor evaluates your actual line, explains in plain English what they're seeing, and recommends what makes sense. The decision stays yours.