Man, it would be great if highly-potent fentanyl that could be administered by just skin contact were available to addicts. Think of how many public health problems disappear by eliminating the need to inject. Not to mention you should be able to get very consistent dosing by just counting patches.
There are fentanyl formulations for patch administration, but they have WAY less potency and are quite niche in application. Not something that has recreational application.
I don't know of any drug that makes drug enforcement police less cowardly, though.