Don't know much about the white stuff but I cured most of my RF inteference buy wrapping my TM wires around 2 RF chokes right at the TM plug. I used 2 chokes and wrapped the wire 2 times on each of them. I didn't have much luck adding the grounds but these issues for each unit are unique to different boats. You just have to keep trying to different things until you find something(s) that work for you.