They do not seem to have cleaned up the list, though: differently inflected forms of the same word appear as separate entries.
Well the've gone a half-way house. They strip (most of) the end off inflected forms of words. For example なる <- dictionary なっ <- なった, なって, なったり etc. なり <- なります, なりません, なりませんでした etc. It also seems that kanji, Hiragana and Katakana have different entries. I don't know how they chose the sources but it seems remarkably short on some words that I would have thought would be fairly common (犬).