Main halyard as temporary topping lift?

Is it crazy to use the main halyard as a topping lift on my DSII when the mainsail is flaked on the boom?
This would mostly be during launching and retrieving (I trailer) and occasional stops to swim.
If that's a bad idea, are there any other slick methods to keep the boom up and the mainsail out of the way that don't involve a boom crutch?
This would mostly be during launching and retrieving (I trailer) and occasional stops to swim.
If that's a bad idea, are there any other slick methods to keep the boom up and the mainsail out of the way that don't involve a boom crutch?