So happy to have found your blog~ first of all, thank you for all the work and care you’ve put into it. Question: will plastic one-time numbered locks work on metal cages (is there a brand of plasitc locks where the numbers don’t wash off?) i do long distance chastity, and for reasons of safety, am nervous about mailing the only keys. Alternatively, have you ever used, or might be able to recommend lock-boxes with timers on them? Many Thanks!