I use "go touch"* Both are used extensively in agility..."go" means run straight until I tell you to turn and "touch' was used with targets so I'm basically using the ring as a target.*
My friends use "go away", "fly", "run", "zoom".* One person I train with used "zip".* Her dog is so confused, often only going half way out and sitting.* I told her "zip sounds too much like sit."* She hadn't realized that before.* Sometimes it takes another set of ears and/or eyes to see the problem.
I'd be careful using "run-run"* You don't want the judge to think it was a double command.* Two word commands are ok but I think it needs to be 2 different words.
I have been using "go-touch" as a correction, so maybe I'll just stick with that one. I need to pick one and stick with it. I initially started with "marco-polo!".. The "marco" made him really mark it when we were learning.