Yes, a lined sewer pipe can be hydro jetted, and jetting is the safer way to clean it. Snaking is riskier. A cable with a sharp cutting blade can gouge or cut the liner wall, so root cutters should stay out of the lined section. Jetting should run at a pressure set for the liner, not the machine’s maximum.
A cured liner is a smooth, jointless pipe inside the old one, so buildup has less to grip, but grease and wipes can still clog it. One liner manufacturer’s maintenance guide calls controlled hydro jetting with nozzles made for lined pipe safer than aggressive mechanical cutting, and warns against high pressure used without knowing the liner’s specs. NASSCO’s CIPP specification even tells engineers to allow for pressure jetting when they set liner thickness.
The blade is the problem with snaking. Installers use rotating cutter heads to trim liner at side connections and to grind out failed liners, and a root-cutting blade on a sewer cable can do the same by accident. A hand snake on a sink or tub drain is fine, because it never reaches the lined main. If roots show up after lining, they usually enter at an unlined connection, and a camera inspection shows where before anyone picks a tool.
Harsh chemical drain openers are the wrong fix too. Caustic products generate heat, and acid ones can attack the resin with prolonged contact. The same manufacturer says the wrong cleaner can shorten a liner’s life or void its warranty. Enzyme treatments are gentler. One honest limit: no public standard gives a single safe jetting pressure for every liner, because resin and wall thickness vary. Tell whoever cleans the line that it is lined.