If I find a search doesn't work well on DuckDuckGo, I just prepend !g to it. Honestly, bang searches are what made me switch, not the privacy thing.
Bangs allow for quick searching of other sites for example !g NASA will redirect you to the google search of NASA !tpb search's pirate bay For the full list
To submit a site to DUcjDuckGo, you need to provide a parameterised search URL that can be submitted (as a GET request I guess) For google you have : https://encrypted.google.com/search?q= what+is+hubski which you would submit to DDG as https://encrypted.google.com/search?q={{{s}}} I'm not 100% sure but I think they send a GET request. Hubski's search is a form that uses POST to https://hubski.com/x You can't submit that to DDG as far as I know. Perhaps one of the devs could make an end-point like hubski.com/search?q={{{s}}} that translates to a hubski internal POST search?