This freewheel has done quite some mileage since it was last wet.

I live in Darwin : the wet is from December to April, and it doesn't rain AT ALL any other time.

This freewheel goes okay now, but it's coming up to the wet season. The freewheel made a popping, clacking sound, when it got wet, when it was BRAND NEW. Since it still worked, the shop refused to replace it under warranty.
But then it went okay during the dry.

When it was oiled, it made the sound MUCH worse, and missed more (but, in reality it missed only very rarely). It sounds like it's building up pressure in the sprag clutch and this is sticking the mechanism ? How would you relieve this ?

Has anyone had this experience with old Japanese Sunrace freewheels ?