Numb

When I first started out masturbating, I used the bathtub method - moving so my hips were right under the faucet. It was great. About a year ago I bought a vibrator, and have used that since. The problem is, I really wish I could get myself off with my fingers, and have only been able to once or twice. It took a really long time and didn't produce a very good orgasm, just tired hands and arms. Using a vibrator is noisy and expensive (all those batteries!). And - I can't get off from the bathtub method anymore. The water goes too cold first. I wonder if anyone else has the inability to masturbate with their hands, and if anyone has found a way that works for us less sensitive women?