You don't need to be that naive. But how clever do you have to be?

Not at all. The protocols for bitlaundry-type arrangements just have to be updated to add random time delays all throughout. No extra effort on the user's side.

There's definitely a lot of extra work, though, that could be done on developing Bitcoin clients that automatically handle stuff like this. (It would have to, without being promted, generate new addresses every so often, and feed them to a service, either which has the time delays, or does it with a patter than would conceal data from traffic analysis.)