There is more than one way that you can hide a button and different layout designs require different techniques for hiding the button or other layout object. See this demo file: https://www.dropbox.com/s/8levaz6deiyzjr8/LayoutObjectVisibilityControlDemo.fp7
Yes, you can hide any button object by using hidden tab like i am using sometime. You can add one tab object having two tab panel. Give names to those tab panel as "Tab1" and "Tab2". The tab size should be just litter bit more than the button size so that the button will be fit into that tab. Put the button inside "Tab1" and "Tab2" must be blank. Then in Tab control setup give "Tab Width" as "Fixed Width" and set 0 pixels and set "Tab1" as default tab panel. Then fill transparent color to that tab and set "None" to the line. It will give you a transparent hidden tab object where "Tab1" is having your button and "Tab2" is a blank one.
Next is when you trigger the script where you require to hide the button, just add the script step Go To Object [ Tab2]. Now this will take you to the blank "Tab2" and your button will not be visible. By doing so user will not experience any kind of tab switching becuase you are doing such in a hidden transparent object.