I believe the Createx website specifically states that one should not wet sand their paints.
Early on when first attempting to use an airbrush I experimented with Createx with very mixed results. Tip dry problems and paint spattering issues were a constant headache. Keep in mind that I was new at airbrushing, a skill I still have not mastered, but I did manage to paint a couple of models with their pearl colors and was very pleased with the results. I understand that their new 4021 reducer (reducer is their word for thinner) has been formulated to reduce tip dry problems. I don't know what the experience of others may be but I found thinning to the suggested ratios on their website resulted in paint that was much too thick to spray effectively in the 15 to 30 psi range that is typical for model airbrushing. As with all hobby airbrushing it seems Createx paints have a learning curve, one that I found to be frustratingly steep. Having said that I am considering having another go with Createx as I especially like their pearls. Hopefully the 4021 reducer and a bit more experience with the airbrush will produce more consistent results.