I realized today that I'm doing something similar ... less tangible than a letter or a bottle, but a message to Kit nonetheless. Often when I pull out my pipes I will play "Dark Island", a tune I learned especially for her years ago, and the tune that I played at her funeral and later at her memorial dedication.
John
p.s. Sorry I've not been posting much recently. I'm not in a good place - Christmas, followed by Kit's birthday in January, and now Valentine's Day - I feel like I'm barely coping. Almost two years now and I still miss her so, still feel the loss like a newly torn wound.