I read it so long ago I really can't comment. It's funny that, you read these things but can you really say that you have read them if you can't remember them. I think at that time I had been reading quite a lot of Burroughs and that always came up (along with Denton Welch - A Voice Through A Cloud) as something that he often mentioned as an influence.
I read both of the above books but I couldn't really understand the link to Burroughs - maybe I would if I read them again now a bit older and hopefully wiser. I have another book by Denton Welch on my shelf now to get round to, perhaps that will shed some light.
One thing about Nightwood, it's a tiny book, must be 150 pages at most, I'd say you haven't exactly got a lot to lose by trying it.