Different kinds of borewell flushing


We are in the process of flushing our community borewells that have dropped in yield. The vendor tells us that there is a low cost compressor flushing with 2-3 kg pressure and a high cost flushing where the rig goes in and flushes the borewell with 20 kg plus pressure. He recommends the high pressure flushing for better cleaning. I want to understand the process better and then decide . Any advice please ?