I have a few wild thoughts about these.
1. How about having a few stipulations for the polishing LE. Bling you own, and bling you gifted, does not count.
2. Have a new achievement: Keep your bling polishing unlocked for seven days (168 full hours) - 25 AP, 30 days (720 hours) - 100 AP. Must be consecutive.
3. Create two new "Abilities". Lock your bling polishing - 6 Ability points. Unlock your bling polishing - 2 Ability points. You can only do these on yourself.
4. Polish 1000 LE Bling in the course of a single day - 3 AP. 2500 - 10 AP. 5000 - 25 AP. 10,000 - 100 AP.