For the toothbrush just rinse it in mouthwash...
If you are that paranoid about germs, well have you thought about cleaning your desk? Specifically your keyboard and mouse. The mouse is loaded with a good deal of germs.
Do you wash your floors much more frequently than normally?
How about chaning your bath towel every 2 to 3 uses?
Just to let you know if you clean your bath room regularly you will not have to worry about crap flying onto your toothbrush. Plus if there is any, you will most likely not get sick...
Also, for the sponge you are supposed to microwave it if you wanted to do it properly.
I guess you are one of those people that are hyped up about antibacterial this and antibacterial that. The truth is you are just making it more miserable for the people in the future as the bacterial will adapt and so on.
I dunno if my soap is antibacterial and I don't care, because bacterial will "fall" off after I wash it with soap...