Drain services in Walnut

Yes, and the mechanism is heat rather than corrosion alone. The reaction generates enough warmth inside a closed pipe to soften PVC and the glue at its joints; repeated use leaves the plastic brittle enough to crack. On cast iron and older galvanised it corrodes from the inside, which on a pipe already narrowed by scale is the last thing it needs. One use on a well-made line will probably not destroy anything. Using it every few months, which is what people do when it half-works, is a different matter.

For grease, genuinely yes — and for nothing else. Dish soap with very hot tap water breaks down the fat film that coats a kitchen waste, which is the commonest kitchen blockage there is. It will do nothing whatsoever for hair, roots, scale or a dropped object. Two warnings: use hot tap water and not boiling, because PVC is rated well below boiling point and a kettle into a plastic waste is how a joint fails; and if it has not worked twice running, the build-up is further along than the method reaches.

On sound modern pipe with nothing unusual going down it, never — you clean it when it gives you a reason. The interval only becomes real when there is a cause: a clay lateral with roots at a joint may want clearing every eighteen months to two years, and a line with a belly in it will set its own schedule regardless. If somebody is proposing annual cleaning on a line nobody has looked inside, the honest sequence is a camera first — because an interval is a symptom of a defect, and the defect may be worth fixing instead.

It depends entirely on where the blockage is. In the first few feet — which covers most bathroom drains — a twenty-dollar hand snake does the same job, and we will tell you so on the phone rather than take the call-out. Beyond that, a cable or a jet reaches distances no household tool will, and a camera answers the question that stops you paying repeatedly. The place it is definitely not worth it is as a substitute for finding the cause: clearing a line with a belly in it is buying the same afternoon again next year.