I am still getting set up but am asking in advance

so I get off to a good start. Are the silicone plugs made to be used in the oven? Can you powder coat a piece and remove the plugs before putting it in the oven and the PC won't run into the holes? Can regular painters masking tape or regular masking tape be used as long as its removed before the piece goes into the oven? And last but not least, what other things are commonly used to plug holes (like paper, wooden dowels or sticks, screws in threaded holes, play dough, etc).