How much NaOH does it take to get arrested?

Serious question: How much sodium hydroxide can I buy without getting arrested? Will ordering it online automatically land me on FBI watch lists? We’ve been playing with a donated Stratasys Dimension 768, and it prints great — but we don’t want to pay for the Stratasys “detergent” that is used to dissolve the support material. In theory, mixing a few spoons of lye into a parts cleaner should work, and it sounds super easy …

Find out how easy it is in PART TWO, unless Tim really does get arrested!