Colloidal Silver is generally considered to be effective in killing the eggs of the parasites, not the parasites themselves. It is used in place of clove for that purpose.
It has other health benefits too, per Bob Beck for one. You might want to research that out. I've used CS for months, home made with distilled water, drinking at least 8 oz. a day. This has caused me no problems & some benefits but most people don't recommend using that much.
It is generally best to do at least a month of parasite killing before doing liver flushes.