Looks like a fake word to me. There are only a couple of uses of it on the Web, and the rest of the mentions are just lists of silly words. The most reliable-looking source, Grambs's 1984 Literary Companion Dictionary, doesn't give any source or etymology.
There's no Ancient Greek word corresponding to it. If the prefix was kat-, kata- "down", I don't know what the -ro- would come from. However, after a moment's thought I believe the form here is an error for 'catharolysis', which would make sense, coming from kathar- "pure, clean". A purification, a purgation, catharsis.
If this word existed, the rest of us would pronounce it /kætəˈrɒlɪsɪs/ or in pseudo-notation kat a ROL ih sis. (Or, better, with /θ/ th.)