Having recently travelled to the US on business I was surprised at the lack of uniformity in security between different airports (I passed through 5 different ones).
I picked up some tools and various other pieces of inventory whilst there and when it came time for me to fly home, I ensured that most of the items were packed either in a heavy duty cardboard box or in my suitcase.
When I checked these items at the airport, I asked if the box could be properly sealed (I just placed some tape on to hold the lid closed) and if my suitcase could be locked up once past security (I put the locks on undone and taped to the case to prevent them from falling off). I also placed a list of the contents of the box and description of the tools inside the box and the suitcase.
When I collected my luggage at my home airport, I was very pleased to see that the locks were in place, locked and with security tape over them and that the cardboard box was also taped up at every seem.
I think that if you do the right thing and follow the guidelines, then you will be OK. I am not sure about the pressurised containers though (maybe butane or propane) but you cannot tell me that every one leaves their can of deodorant or shaving cream at home??