That is colloidal silver you are talking about at the cvs, but it is too weak of a concentration to make feminized seeds out of.Pretty sure you can just go to CVS and get colloidal silver solution already made up for ya.
http://health.cvs.com/GetContent.aspx?token=f75979d3-9c7c-4b16-af56-3e122a3f19e3&chunkiid=111807