The badge idea is a good idea, but wont stop someone from creating another account and doing this again and again. Best way to do this and if you truly want to put an end to this is pretty easy.
If someone wants to apply for a logging opportunity,
1-have them pay for the product up front
2-have them pay for 50% of the product up front
At the end of the log, the money will be returned in full. This will solve any forgetfulness and should ensure that the logs are updated on a timely basis. The agreement prior to accepting the logging opportunity will be part of the process for accepting the individual. If you are serious about logging then you should have no worries about accepting this term and for your efforts, you are still getting the product for free.
It is harsh, however some of these products are between $40.00-$90.00 a bottle and this can get pretty expensive of the course of a year.