Given the fair warning so generously given me by others, I was prepared for the very worst but surprise, surprise...it wasn't all that bad, after all.
I can't say it was very compelling, true, but it wasn't "dreadfully boring" either, as it's been called. There were some cringe-inducing moments to be sure, particularly when Elisha Cook 'freaked out' towards the end - and I'm still not sure what function the older of the two ladies was supposed to be occupying within the group, but I did find the lesbian undertones (with good reason since I did find Karloff's secretary rather attractive myself) surprising for a schlocky B-movie of its era! So, no great shakes definitely but an adequate time-waster nonetheless...though the voodoo promised by the title had nothing to do with the man-eating plants we eventually ended up with!
Maybe when I get more acquainted with Karloff's other programmers, my opinion of this film will take a nose-dive but so far, it was a watchable diversion and nothing more; besides it was nice to see Karloff in a straight, i.e. non-menacing, role - though it was somewhat uncomfortable to watch him stumble about on many occasions (due to his illness and old age).