Killing bacteria in their mouths is what humans are trying to do but what really they want is to regulate said bacterium because you also have a good flora of bacterium as well. Killing all of them is actually wrong much like destroying an ecosystem.
Imagine keeping your toothbrush in such a solution of good bacterium until you need it again. First of all, the correct bacterium would help rebalance the ecosystem in your mouth everyday and also as a placeholder the good bacterium would compete against anything that may try to live on your toothbrush while you aren't using it.-- sartep, Nov 11 2004 Colgate probiotic - coming to a fridge near you.
Alternatively, make your own: take some live yoghurt, talcum powder and some liquid mintiness (I know that has a name, just can't think of it). Mix all together and apply to teeth via brush.
top idea, btw. I admit I was expecting some sort of cargo cult, worshipping a discarded toothbrush deep in the jungles of Borneo. +-- moomintroll, Nov 11 2004 sartep, having found a toothbrush deep in the jungle, carries it many miles, seeking its owner. “God,” he says to himself, “God must have dropped it.” Seing Una, he approaches with due humility. “Are you God?” he asks, bowing deeply, holding up the toothbrush. “Are you Colgate?”Una, feeling magnanimous, tells sartep to keep the brush. But sartep is of a primitive tribe, a tribe without clothes, and therefore without pockets. “Where shall I keep this sacred brush?” he wonders. Then he has an idea! He puts the brush in his mouth and carries it there. But soon his mouth begins to cause him pain; his teeth become black and fall to the earth. Frightened, he spits out the evil gift and fills his mouth with mud, as his people have always done. He was foolish, he sees now, and, cursing the Una-Colgate, goes back to the old ways.-- ldischler, Nov 11 2004 I thought this was going to be a shameless criticism of British oral hygiene. (ducks and runs)-- contracts, Nov 11 2004 <observes to oneself that smacking someone in the mouth might very well damage their perfect teeth></ototssitmmvwdtpt- see above> :)-- po, Nov 11 2004 random, halfbakery