Nice theory.... but i have different opinion about the drug, at least, you almost make me change my mind. but i have one point about your theory.
I think haibara already have that sense even before she drunk the drug... Remember her meeting with kiichiro numabuchi? She said something to conan about her weakened sense and also about her sister... That even she could sensed her sister "BO scent" at their last meeting.
So according to your theory about getting enhanced sense by drug then she must already drunk the drug before her sister death to gain that sense... I think you must consider this contradiction and have other explanation to support your theory. But you've got a point in your theory about "the real effect of the drug". With little information about the drug there still many possibilities of the effect of APTX and the research goal.
ran mamijo kun
katara kare anya masuno