A method of cleaning a waste water vessel 100 for the waste water industry comprises adding a first quantity of a first reagent to the waste water vessel, adding a second quantity of a second reagent to the waste water vessel, the first and second reagents being reagents that react together in an exothermic reaction whose products comprise sodium chloride and nitrogen. Heat generated from the exothermic reaction causes solidified fat, oil and/or grease (FOG) deposits 105 in the waste water vesse...

A method of cleaning a waste water vessel 100 for the waste water industry comprises adding a first quantity of a first reagent to the waste water vessel, adding a second quantity of a second reagent to the waste water vessel, the first and second reagents being reagents that react together in an exothermic reaction whose products comprise sodium chloride and nitrogen. Heat generated from the exothermic reaction causes solidified fat, oil and/or grease (FOG) deposits 105 in the waste water vesse...