Research in the United States shows that the failure rate is 15% to 28% per annum. And, both men and women are frustrated by having to interrupt at the last moment. Washing and cleaning the genital area before and after coitus with unscented mild substance that may be prescribed to you can help as well. When a mixture of different substances is rotated at extremely high speeds within a closed path (in your case a closed container), substances of higher mass often go on to the outermost path and lighter particles experience the nearest to rotating axis. The same principle can be used in centrifuge oil cleaning. The first basic is you are what you eat!