What collection of items could you buy that would make the cashier the most uncomfortable?

Don't forget the C-4.

I would have to make my own.

If so you forgot acetone, moth balls, fertilizer and a Gelatin of some sort.  Flexible baking cups are also nice - just saying

The fertilizer is ammonium nitrate. Difficult to get a hold of.

Substitute cloudy ammonia and tincture of iodine. Ammonium iodide is touchy, though. Shock sensitive.

I have made it in small quantities. Ammonium triiodide. Ammonium crystals and concentrated ammonium hydroxide. I had some fun with it with my students. Large quantities can be dangerous and pure iodine crystals are difficult to obtain. I had about 500g in a jar in my lab.

It's safe enough while wet. As soon as it dries, BOOM!

Not safe when wet. I had a beaker of it set aside, ready to filter and it started to bump. I took it outside and it exploded. Glass everywhere, and dead grass all around. I never made it again.

Element simple, Magic Grow and straight alcohol.  Figure out the rest terrosrists are idiots. Have eliminated in my career. All through nascent stupity.  Similar to what I am displaying tonight.

Been awile, just saying

Not reallly, Scotts plus Kerosene simple Jihadi chemistry.  Element you are too narrow in both your focus list and target list

Yummy...ham on matzo crackers.

My buddy Dan and you are soul mates.  Matzo with pork and or Fois Gras is a favorite.  PS Dan is Purple like you, his dad is really purple think the big M..... Element Sidbar me for details. Now Isreali wines and Brandies are excellent did you know?