It will dissolve if you wash it. If using under NMF like any putty you must seal it with a clear coat like Future so the surrounding finish will match the filled area.
I’ve been building models for over 50 years and have never washed a model except resin parts that tend to have mold release oils. I either use compressed air or a soft flay brush to gently remove dust and junk. To remove fingerprints prior to paint I lightly wipe the plastic down with rubbing alcohol.
If it thickens the tube add a few drops of distill water and shake, it will become soft again.