Full bladder hits prostate better than Aneros or any other toy I’ve tried, is there something I’m missing?

I’ve tried

* Prostate wands
* Prostate vibrators
* Prostate massagers (moving/stroking model $$$)
* Prostate plugs (EG Aneros)

The longest orgasm I ever achieved was using a full bladder, some soft gentle weight resting above the bladder to rock it, and an Estim pad to lock the kegel exercise muscles.

Cost way less than all the backdoor toys I’ve tried to date.

Is my prostate just too high/low/far from the intestinal wall or something? I know it can vary between guys.