Sixty Grit raised an interesting point back here about substituting everyday chemical substances for commercial products. This is a very DIY approach and reminds me of a thriving barter economy.
It also reminds me of a Jeffersonian Ideal. In his view, patents were a sort compromise: monopoly rights granted for a fixed term in exchange for a full disclosure into public domain. The latter is never emphasized, and yet the Patent Office essentially publishes an online "how-to" manual for many many useful inventions. They all come with expiration dates, the one date which is rarely emphasized. Why do you suppose that is?