PIF rules are whatever you make them. If it's a used soap, you can simply state whether you loaded from the puck (implied) or scooped out some and that a brush never touched the puck. It's up to folks who wish to enter to determine what they're comfortable with. I would recommend trying to ensure that no brush hairs or whiskers are on the puck, as that gives some people the heebie jeebies.
PIFing Soap Rules