Now, I get that a wizard crossing a threshold uninvited will leave his power "caught" in the threshold, or most of it.  My question is this; If, say, Harry were to make a pair of potions, one that made someone very strong, and another that made them very tough, and gave them to, oh, Murphy, then sent her into a home uninvited, and she takes the potions after crossing the threshold, what happens?

Do the potions have no effect?  Full effect?  Somewhere in the middle? 

Same question for something along the lines of Harry's force rings.  If he made one of those for Murph, and she went inside a home uninvited with the ring fully charged with kinetic energy, would it work?

I'm going to be dealing with these questions in-game soon, and I'm waffling on where to go with it.  My first inclination is to lower the effectiveness of the potions slightly, reducing the effective strength one level, and to have the enchanted item fail completely, but I'm open to other suggestions.

Thanks in advance for the input.