Ecologic has a series of mint/lemongrass based sprays that are intended to kill by contact.
However, I've found they also make an effective barrier if sprayed along baseboards, window/door frames, and the outside of the house.
I will warn you, if sprayed indoors prepare to leave the house for a bit. It's not that the sprays are dangerous so much as they are offensively mint smelling.
We spray in the spring and it seems to do a fairly effective job here in the Midwest.