A simultaneous optical signal dropping and cleaning scheme is presented by utilizing fourwave mixing effects based optical logic gate (AND and NOT) in optical fiber. Two synchronized square pulse control signals with inverted intensity, coupled with data stream, produce fourwave mixing effects to implement dropping and cleaning functions. Simulation and experimental results are successfully demonstrated with nonreturn to zero (NRZ) data at 10 Gb/s. The proposal may work at higher bit rate with transparence for operation wavelength and data format.