A new fritted filter should be washed by suction with hot hydrochloric acid and then rinsed with water before it is used. This treatment will remove loose particles of foreign matter such as dust. It is advisable to clean all fritted filters as soon as possible after use. This will prolong the piece's life, and the filters will be clean and ready for reuse at a moment's notice. Drawing water through the filter from the reverse side with a vacuum pump is also effective.
Some precipitates tend to clog the pores of a fritted filter.
Treatment here must be by chemical means. Click on this link for a chart of suggested cleaning solutions.