Feeding keris in museums

[Georgia]

Hello all
I am coming to the end of my studies and am now in the process of tying up loose ends on my keris thesis. Firstly I want to say thanks for this great resource, it's taught me a lot. The obvious passion so many of you have for presenting problems then nutting them out in a (usually!) civilised way - between so many contributors - is inspiring!
I have a prob here now so please let me know if you can help. Have any of you heard about the practice of placing a bowl of water inside keris display cases as a form of offering? I imagine that being on display this would mean it's something that occurs (or has occurred in the past) in museums, although perhaps it is elsewhere too. I've gone over all my references and can't find it anywhere, so I'm thinking perhaps it was just something I was told in a conversation. If any of you have any suggestions I would be very grateful!
Cheers
Georgia