I've been getting very good results by placing warm water on a crystal illuminator [a small 7 watt light in a base that illuminates crystals from the bottom]. Not only does it look really cool and make everything visible in process, it also induces a very gentle thermal convection current that's enough to disperse the ion cloud and interrupt current pathways but not enough to disturb the oxides.

A laser pointer or strong flashlight allows for seeing the ion clouds forming as well.