Shaw, in order to not bring in bugs, re-pot just before bringing it indoors. Some of the old soil will remain, but if you shake it off to loosen up the root ball, and add new sterile soil, you should be fine. If you're still worried, a douse with some soapy water should kill off any remaining bugs in the soil. Spray the plant's leaves with soapy water, too. It will clean and shine them up. About 1/2tsp. dish soap to a quart of water is plenty.
I have no plants in my house for that very reason - the dark, moist environment in flower pots is ideal for roaches to hide in. My Vanda orchids will have to come in for the winter, but they are bare-root.
But my garden goes year 'round here, so I don't need them. We have the windows open most days in winter so all the fresh air and oxygen gets into the house. I believe in what Cinta says about plants cleaning the air and producing oxygen indoors in winter up north, where you are heating and re-circulating your air all winter. If you want your plant to produce oxygen at night all you need is a grow light. Fluorescent lights also make plants produce oxygen, so your sisters at the hospital certainly were out to lunch on that.
