extra oxygen they provide? You mean just from spilling water into the tank? Wouldn't your filter do that with or without the biowheel? The biowheels are designed for maximum biological filtration...are you just using them in your specific application in another way? I just can't see how rinsing them helps anything at all....I suppose if you have clear water and good parameters then you aren't hurting anything, but I can't see any benefit to rinsing them (or to bleaching your micron cartridge, for that matter) but I can see some detrimental effects that it might have.
JMO.
JMO.