I finally got the PPS cup for the turbine I bought last year and am trying it out for the first time. How does everyone clean the gun between products when using these? I usually would rinse the cup with water then spray some through the gun. Unless I clean the insert or use a fresh one that doesn't work here. I thought I'd hold a cup of water under the gun and dip the adapter in it but that doesn't force it into the gun since the cup isn't pressurized.