Review (5/5): Wipe it off, and it will last
I went through a few Oral B toothbrushes before I realized that leaving the toothbrush head on the handle after using it allows water to run down the stem into the electronic circuitry inside, which will eventually cause it to short. They'd only last about a year or so. When I opened the handles to take out the batteries for recycling, it was obvious that moisture intrusion was the cause of the problem. Also, others have mentioned a brownish residue settling on the recharging base. It finally occurred to me that both of these problems would be solved by simply removing the toothbrush head and wiping off the stem after each use. I just stand the toothbrush head on the counter by the charger. Keeps everything looking clean and like new.