applying force to a stuck nut or bolt

[connerm]

I am trying to find infomation about a method of losening tight nuts and bolts that incorporates the application of force over a long period of time. Theory goes like this...attach a wrench to the bolt or nut and apply some force to the wrench in the counter clockwise direction and hold that force there overnight, or for some extended period of time. Of course you would use a rope or a turnbuckle or a bungie or something. Has anyone ever heard of such a method? I swore I read it on a thread here.