For hydro-jetting, isolate the line, install a backflow preventer, start with lower PSI, then increase as required

https://delta-wiki.win/index.php/Coming_From_Blockages_to_Clear_Lines:_Just_How_Hydro-Jetting_Improves_Septic_Tank_Maintenance

For hydro-jetting, separate the line, install a backflow preventer, start with lower PSI, then increase as needed, using suitable nozzles to search biofilm, roots, and scale without damaging pipes.