"I-Pickling" kumxholo wokucutshungulwa kwensimbi ibhekisela kwinkqubo yeekhemikhali ezisetyenziselwa ukususa ukungcola, okufana ne-rust kunye nesikali, ukusuka kumphezulu weentsimbi zetsimbi.Inkqubo yokuchola ilungisa intsimbi ukuze iqhubekeke phambili, njengokugalela, ukupeyinta, okanye ukuqengqeleka okubandayo.
Kubalulekile ukwenza inkqubo yokuchola kwindawo elawulwayo ngemilinganiselo yokhuseleko eyiyo kunye nemigaqo yokulahlwa kwenkunkuma, njengoko iiasidi ezisetyenziswayo zinokuba yingozi ebantwini nakwindalo esingqongileyo.
Inkqubo yokukhetha isetyenziswa ngokuqhelekileyo ekwenzeni iimveliso zetsimbi ezahlukeneyo ezifana neendawo zemoto, iipayipi, izinto zokwakha, kunye nezixhobo zombane, apho indawo ecocekileyo kunye nengenasikali ibalulekile kwisicelo sokugqibela.