deterge

wipe away; to wash off or out, cleanse; chiefly in medical use: to clear away foul matter from the body; "This drug is powerful enough to deterge"

उसने कहा था कि क्रिस्टल साफ करना अच्छा है, इससे उसके नकारात्मक विचार भी साफ हो जाएंगे।

Cleaning with water and usually with soap or detergent.