The object of the invention is to provide a method and apparatus for treating membrane containing material with electrical fields and with an added treating substance. With the method, a plurality of electrodes (121-128) are arrayed around the material to be treated and are connected to outputs of an electrode selection apparatus (110). Inputs of the electrode selection apparatus are connected to outputs of an agile pulse sequence generator. A treating substance is added to the membrane-containing material. Electrical pulses are applied to the electrode selection apparatus and are routed through the electrode selection apparatus in a predetermined, computer-controlled sequence to selected electrodes in the array of electrodes, whereby the membrane containing material is treated with the added treating substance and with electrical fields of sequentially varying directions. The routing of applied pulses through the electrode selection apparatus (110) to selected electrodes (121-128) can be done in an enormous number of ways.