Are you familiar with Terahertz technology? Also known as submillimeter wave or Tetrahertz.
Terahertz radiation falls in between infrared radiation and microwave radiation in the electromagnetic spectrum, and it shares some properties with each of these. Like infrared and microwave radiation, terahertz radiation travels in a line of sight and is non-ionizing.
Like microwave radiation, terahertz radiation can penetrate a wide variety of non-conducting materials. Terahertz radiation can pass through clothing, paper, cardboard, wood, masonry, plastic and ceramics. Wiki
Because of these properties, several companies are producing detectors that can detect things others would not be able to. This passage is from one such company, Teraview
Explosive materials absorb THz light strongly at certain terahertz frequencies but not at others, and this 'terahertz fingerprint' can be used to identify an explosive, and distinguish it from clothing or other inert materials. Because clothing is transparent at terahertz frequencies, the THz light can pass through several layers, including common garments and shoes. TeraView has also demonstrated the technology is capable of detecting different types of plastic explosives through clothing, including PETN (Pentaerythritol tetranitrate).
There are a few, but not many others. Though this technology has existed for some time, practical and less expensive detectors have only been appearing in the last 5 years.
Have I ever used one? No, but I would consider getting one if the price was < $2000. Which I don't believe it quite is.
Just something to consider, if the budget is there...