Trailer brakes is always the first and best option in my mind. Along with letting off the gas. Trusting yourself to accelerate when the poop is hitting the fan is asking a lot. Maybe some well trained Navy seal has the focus to pull that off but I know I don't. The natural human reaction is to hit the brakes. The best you can hope for is to let off the gas and stay off the brakes.
I'm sure in some situations I'd be able to accelerate but trusting that I can do it in an all out emergency is a stretch. When I'm in "RV driving mode" my hand is always ready to grab that lever in an instant. And the funny thing is I'm in a 5th wheel and rarely have to worry about sway. My habits from years of towing trailers stick with me.
