There are duckduckGo privacy settings you can set. I'm not a big fan of a cloud store for your settings and thankfully duckduckGo allows for settings parameters in the url[0]. You can do things like require POST instead of GET, redirecting, forcing https etc. Once you get your search and privacy settings how you like them, take the resulting url and make an openSearch plugin out of it, manually or with something like my mycroft project[1]. Now any searches use your settings, no account/cloud settings needed. It's then easy to throw in every browser you use. Technically a plugin.
PS. If you need a favicon from any site for a plugin or otherwise, easiest way I've found is https://www.google.com/s2/favicons?domain=duckduckgo.com. Will grab it from wheverever the sysadmin decided to put it.
[0]https://duckduckgo.com/params [1]http://mycroftproject.com/submitos.html