The problem that may crop up (IMO) is the knuckleheads going outside the SOP. Learning how things are secreted or concealed may help you to find something during a patdown or bag check, but the reason for the search (in the first place) is to clear the individual of WEI. We are not to specifically seek out things that are not WEI. The fine line is when something like illegal drugs (to use your reference) are found, they are to be reported to the local LEO. We are not to go into a bag (or pat someone down) with the specific intent of "finding drugs", we are to go into the bag looking for WEI, and if we find illegal drugs, we contact the LEO. I know that some folks don't see much of a difference in those actions, but it is there.

Learning concealment methods is a good thing, it can help you when you have that bag check and just can't find what the Xray operator is showing you - you see a knife on xray, search the bag where it should be and.... no knife. Go back, rerun the bag, and there is most assuredly a knife there, most TSOs have had a similar situation occur. This is where learning those concealment techniques can be helpful, it can show you different ways of looking at the bag and what can happen in them. I understand what you are getting at with the misleading point, but the SOP and all training I have been through have always told me that we are not looking for drugs, we are looking for WEI - discovery of things like illegal drugs in the process of looking for WEI, are not the focus, but they are to be reported if found.