Provided are products of manufacture and methods for the removal and/or destruction of a biofilm in situ, e.g., a gastro-luminal biofilm, and for the treatment or amelioration of biofilm-associated diseases, infections and conditions, including and GI luminal infections. Provided are devices and apparatus, and methods for using them, for the removal, disruption and/or destruction of a biofilm in situ, e.g., a gastro-luminal biofilm. In alternative embodiments, provided are devices and apparatus, and methods, for enhancing biofilm dissolving or disrupting agents, or for administering biofilm dissolving or disrupting agents, where in alternative embodiments the biofilm comprises a gastro-luminal ‘unstirred layer’, adherent layer or gastro-luminal mucus layer; or the biofilm comprises a matrix or a DNA-containing layer, or alternatively the biofilm comprises a polysaccharide gastro-luminal peripheral layer.