My 95 does not leak oil externally, but if I use Water Wetter, crankcase oil transfers to the coolant water

(I'm not talking about an
oily film on the coolant water, but rather true oil buildup in the overflow bottle accompanied with missing oil from crankcase.... anywhere from .5qt to 1 qt. every few weeks).

But it's still an oil leak related to head gasket... odd that it doesn't happen unless Water Wetter is in the coolant.... any theories why???
No external leaks of any kind:)