I have designed a holder for the head of your electric toothbrush.
It is sized for heads of the brand Oral-b ( 10mm diameters).
To avoid water spottings I designed a gathering place for drops coming from the used head.
The product is stable and able stand on its own. But you can as well hang it on the wall as I added slots.
If you wish you can affix names as shwon on my pictures.

EDIT: I have added a 5 degree angle, so the heads won't slip off!