I wouldn't do this. The capillary action of the liquid will probably make the whole model a mess, or at least his arm.
What about cutting off his sword or sword arm, repainting it and putting it back on. I've done that before with a metal model and it isn't too bad, just a little touch up paint where you cut.
I gave your mom some of my capillary action. BAM!
Give a man fire, and you keep him warm for a night.
Set a man on fire, and you keep him warm for the rest of his life.