So, there's an underwear run near my university on Wednesday night

I'm currently cutting, and while I've made it down to ~12% bf, my abs aren't exactly visible or anything

SO -- I know that there is some quick stuff you can do to LOOK a little more cut for a short period of time, a la dehydration and a short workout just before the event

can anybody give me some more details on things like this? (how EXACTLY should I go about dehydrating? just drink very little water and eat very little?)

thanks in advance, /fit/