Yep, sure can not see how a toothbrush would be any better if your concerned about wearing out the silicone. I have used magnetic cleaners, both float and non float type for years and none of my tanks have worn silicone. I have one tank that gets a lot of sunlight (FW)and it needs cleaning daily if I expect to see whats in it, and its silicone seals have held up just fine, and its probbaly beenin use over 6 years now, outside under a gazeebo all this time.