I really liked that finger one even though I was inconsistent as well with my first, but here are two other suggestions:
One step ahead!!
Safety toothbrush: A toothbrush designed for safety. Designed so well, it's an award winner! Our oblong toothbrush is safe enough for babies as young as six months. It prevents over-insertion into the mouth and reduces risk of injury, and it's easy for tots to manipulate, too. it's a 2 pack for 6.95.
OR
Baby's first toothbrush:This toothbrush feels so good! Dentist invented! Baby will enjoy biting down on this soft, patented toothbrush — and when she does, it will gently surround her teeth, cleaning all surfaces. Its soft, tiny bristles not only remove bacteria, they soothe tender gums. For 4 months and up. Colors may vary. 2 pack for 13.95
Good luck