I have a Pennsylvania Flyer 0-8-0 LC that I bought for my son. I modified it with a DPDT switch, so it can be run with the remote, or directly from track power. I should mention that I run 3 rail DC/DCC on all of my layout. For his trains he uses a 1-15vDC HO controller. He can still use the remote for sound when he wants.
If you don't have DC controller, add a bridge diode to the engine, or between the AC controller and the track.
This way you set the controller to the speed you want , and just switch on the power when needed.