The water jet reaming tool can avoid the need to replace a toilet (17). The curved handle (19) allows the user to stay at arm's length away from the difficult removal of mineral deposits (13) which prevent sufficient clean water (14) to flush the toilet. A reamer element (12) stands ready at the other end of the handle (19) to enter a clean water jet (15) under the toilet inner rim (16). The user views (11) the water jet (15) and the point 26 via lines of sight (18) from the reflection in the metal mirror (30) attached to the reamer element (12). The user's wrist motions cause the handle (19) to rotate the reamer element (12) and grind the mineral deposits (13) to dust.