Hey,
I recently stripped an entire 3.5k army of marines, and it was largely hit and miss, due to not knowing what I was doing. What I've picked up from it is that the introduction of water into the mix really messes with the stripping effect: Instead of lifting the paint off, it returns the paint to some of its previous consistency, and essentially repaints it back on. Hopefully that made sense, it really isn't nice. To avoid it, don't introduce water
AT ALL, not even to clean the brush (or whichever tool you are using).
For the models with the layer, it's best to let them dry and then re-bath them in a fresh solution.
Also, it does niggle away at glue that is either weak, or doesn't have enough to keep the bond strong on the model. Just reglue it.
Never been able to paint white myself, so I can't help on that.
GL.
--> Grayspear