During inkjet Hewlett Packard (colour) cartridge regeneration process after hood and sponge removal you may notice that the cross colour contamination. A contaminated sponge may affect your printout(e.g. instead of green colour your inkjet prints in yellow or instead of red you get rust colour printout.
Rinsing the old sponges is not enough. It is advisable to replace them with new ones. In their attempt to achieve the best results (bearing in mind the regenerated cartridge quality) remanufacturers replace sponges during every regeneration even if there are no traces of cross colour contamination.
AGAWA.PL recommends replacing sponges at every cartridge regeneration.