design idea - Dental floss

I bought a box of dental sticks/floss harps (one stick pictured) but it seems such a waste to use them and throw them away, although I must admit, having the floss held in a bow is much better than pulling floss from a reel and doing the sawing action with both hands (bleeding gums!). 

So I've been thinking about combining the best elements of both.  A replaceable cartridge holds the floss, which with a simple stop device allows the user to pull off one revolution of floss from the reel.  The old section of floss is held fast and cut off in the floss lock.  Replacement cartridges could be sold, greatly reducing the ammount of waste.  There may be a few hygeine issues, but the one piece device could be easily washable, which is only the same as using a toothbrush.