any reason why you need to do that ?
as far as I know its neccessary to be in the scrathbox environment to run anything in there as for all practical purposes its another system (virtual ) in your linux system.

You could try running them in a script with some sleep ? not really sure if its worth all this, depends on what you are trying to achieve perhaps.
I use a linux environment and I have terminals where im logged into the scratchbox and also have Xephyr up. Didnt find any problems in using it this way so far