A method for cleaning a metal surface of a metal component of an industrial plant is disclosed comprising measuring the electrical resistance RA1 of a metal component over a cleaned area of the metal surface with a resistance meter, comparing the electrical resistance RA1 measured with a pre-determined electrical resistance value RDET, assessing whether RA1 is greater, smaller or equal to RDET, and repeating cleaning if the electrical resistance RA1 measured is greater than RDET, or terminating cleaning of the surface area of the metal component if RA1 is smaller than or identical to RDET.