Okay, this is genius actually. I've never thought of it. But yes you absolutely could do it.
Two problems.
1)They would have to never ever ever be exposed to temperatures above body temp. If they are, they become denatured and no longer work.
2)The law covers whats known as "constructive possession" meaning that having all the necessary means/ingredients on hand WITH the intent to make the substance is still considered possession of the substance.