[EDIT_2 Note: removed references to the bead being antimicrobial [anti-microbial beads were from a similar product from another company]. This primarily reduces the number of concurrent but still, the brushes don't get nasty because the increase in fresh saliva performs the antimicrobial action]
These are technically reusable. I just make sure there's no chunks of food in the bristles and just put them back in the package. They last 4-8 uses this way with no foul tastes or odors (unless you don't like the taste of the bead). They clean as well as a standard toothbrush an are great for the glove box.
[EDIT_1] Oh, and when your done using them for your mouth, they make great little scrub brushes for all sorts of stuff (I've used them to help work out stains in clothes, cleaned grout, and used one is a small back scratcher so far).
The price is great, the cheapest I've seen them (on sale) was $1 for a 4 pack (so $12 for 48), although most places are $1.30 for 2 around here ($15.60).
The only problem I've ever had with them is that the bead kept falling out in one of them.
And the only problem I have with this particular woot is that we only get to order ONE flavor. WOOT! Can we get a variety pack? Please? I'll be in for 3 instead of 1!