More ' metal ' cures

Many of us are already aware of the various types of "metal" element cures such as:
1. metal windchimes
2. grandfather pendulium clock
3. 6 iching coins string together with a red string and some comes with a red tassle.
4. Personalised copper ruler (sold by some FS practitioners at a marked up price.) Which is still valid as it is still considered as a metal cure.
So, what about the use of "metal in salt"?
Here, some FS practitioners advice placing 6 iching coins in a container especially a glass container and add water / salt to this combination.
Is this valid?
Well I personally feel that this is more of a Western practise rather than in the East.
It is still valid to do so. However the following consideration:
1. In Asia or countries with high humidity; water has to be constantly `replenished' as the water in this container (added with some salt) vapories fast.
This cure would require frequent maintenance. As the owner has to constantly check on the water level and may need to frequently feel up with water again.
2. It would not be ideal to place it at a `dead corner' where there is no ventilation as the reaction of water/salt with metal; could cause some reaction and create some gas emmission.
3. In countries with less humidity; it can still be used and less maintainance.
Warmest Regards,
Cecil