It is a barrier for me too. Last night I tried again, first at 12 oclock, and again at 4. The 12 attempt, did induce SP, and I got some auditory hallucinations, but no WILD. I was attempting a V-WILD, and again at 4, no luck, but the intentions of both V-WILDs featured in the following dream, in which I was lucid for enough time to accomplish my objective. Interestingly enough, a DC whom I know from RL told me I was dreaming, and told me to accomplish this particular goal.

Keep at it, you will probably get used to it. I would imagine it would be easier if you were under the effect of a mild drug with a relaxing effect*

*an idea, I dont do drugs.