I have actually never had a pocket rocket fall apart on me - I still have the original one I purchased over 10 years ago, but the motor died in it, so I replaced it with the Devices of Desire version:
http://littlepleasures.org/devices-o...ket-rocket.htm
I like this one because it has a soft coating on it, so it isn't just hard plastic, and also it is waterproof, so you can use it pretty much anywhere.
I know there are different brands, so perhaps if you switch brands you'll have better luck. On a side note, even if you are replacing it, they are usually only around $20 or so, so at least it isn't a huge investment.