Can you? Sure? Should you? No way.
Get a controller. The few dollars it will cost you will be small to the possible lawsuit you'd have to endure and eventually pay if you got into a wreck and it was your fault....let alone personal injury or death that could happen from not having the proper gear installed and running. There is a reason brakes are built into RVs and towables over a certain weight....I may even be so bold to say that some states require by law that you have working brakes on your RV over a certain weight.