Not sure what Brewie says but PBW and rubber gaskets and plastic pieces are not good bed mates.When I have done a full clean I keep adding in PBW, I'm guessing that should do a good job cleaning the plate chiller. Then towards the end of it all I toss some StarSan in with the water when it is in the rinse phase. I just sort of have guess on the timing but figure that is good enough. I'd be nervous to pull the plate chiller out after seeing the inside of the B-, I've yet to open up my B+ though.