It depends on what you mean by "float."

If the model has a shallow power glide on final approach and you would like it to be slow but steeper then there are two possible solutions. If the shallow glide is caused by too much thrust when the engine is idling, then the answer is a lower pitch prop or an engine that idles slower. The excess thrust can also be overcome by adding a lot of drag in the landing approach. Lots of rudder and opposite aileron will side slip the model and the huge drag of the side slipping fuselage will bring the model down more steeply. You just have to straighten it out before touch down. Yet another solution is to add inboard split flaps. The flaps will slow the glide and also steepen it. You can even use flaps with lots of holes in them like the dive breaks of the Douglas Dauntless.

Increasing the wing loading will reduce maneuverability and raise the stall speed. I think you will find it is a poor way to compensate for too much thrust from an idling engine.