I would say that since you are already have your rockwool in hydroclay, there is no reason to wet the rockwool.

In your DWC setup, how is the rockwool getting wet? If you have the nutrient solution high enough so soak it, lower your solution. You could leave the rockwool completely dry and allow the roots and hydroclay to get wet and that should solve the problem (and potential for others) by not allowing moisture in the rockwool.

Nice setup also