This is not correct. The concentration supported by the literature is 1:250 which is 4 mL f10sc in 1 L of solution, which in studies is normal saline, but as most don't have normal saline readily accessible, distilled water seems to work just as well, anecdotally. Treatment can be 1 to 3 times per day for 10-15 minutes for each treatment and, ideally, should be combined with antimicrobial treatment.
3mL f10sc in 1000 mL is a concentration of 1:333