Halo stays in your piss for two months...two weeks would most likely not be sufficent to clear ox or winny. Three weeks is the given time for oral winny and ox, and inj winny sits in you for up to two months. Some freaks might be able to get out oral ox or winny in two weeks...super low BF% and hydration marathons. If you used both though, two weeks won't cut it. If your tested the night of the contest...just go home. You will test very very postive if you hit up halo or inj winny. There are no such things as test masks. They are all scams.