Additional external prostate stimulation while using an Aneros?

I've been occasionally using an Aneros for approaching ten years and enjoyed it despite getting little more than a few P-waves. It's very likely that it's the mental side of things that's holding me back; I'm anxious and controlling at the best of times and on an anti-anxiety SSRI. It's likely that I would probably have much more joy if I could relax while using it, but I haven't found a way to do so yet. (Solutions involving trees, even if they were legal in my jurisdiction, hold no interest for me – and perhaps it's hypocritical for me to be OK with taking Citalopram when I'm not prepared to consider anything more herbal, but that's an argument for another time and another subreddit.)

In a session today, when reasonably aroused and making the usual deliberate contractions to move the Aneros, I found I was able to trigger some light involuntary contractions by applying a vibrator to my stomach at the base of the penis (i.e. very close to the shaft of the penis, but not actually touching it), presumably giving the prostate additional stimulation through the bladder. Sometimes I've used traditional penile masturbation techniques to reach the point of no return, then stopped and applied indirect pressure to my prostate that way to get me over the edge; it's probably as close to the hands-free orgasm that I so crave as I'm going to get.

1) Anyone else here do this? 2) Is there any reason why this might actually be dangerous? 3) Is there any reason why this might stop me from achieving other things with the Aneros? 4) If it's a harmless enough thing to try, are there any better approaches to this technique to use instead?