If you're gonna act like a dog it would only be right to carry a bone with you.
Or, in your case, a boner... Carry a dildo for the entire time, whenever you move it has to be balls deep inside of you (your choice of hole).
When you arrive at your target, get on the ground and ride that dildo as fast as you can until your legs give out or 5 minutes are up.
Of course you're going to have to have it inside you until you're dressed again - and preferably also on the way home.
If you lose the dildo at any point, pick it up, walk back to where you started and try again - imagine losing it while doing your last task...
