the present invention is a method for using a horizontal , continuous process auger centrifuge to separate the granulated material of a container from whatever liquid residue remains within the container . though this technology is suitable for many diverse applications , a primary objective is the continuous separation of the recyclable plastic of a motor oil container from the remaining reusable motor oil within the container after the container has ostensibly been emptied . it is an objective of the method to accomplish this separation in an economically advantageous manner which uses neither a solvent nor a wash process , and which reclaims the oil in a suitable state for reprocessing . in a second method , a rinsing mechanism is employed by which a residual liquid waste , such as soap , may be concentrated and separated in a first rinse stage without introducing the residual liquid waste in dilute form into the waste water treatment process .