Conkers and Spiders

I met up with my mum today.

During lunch, she told me about her plan for reducing the number of spiders in the house. Apparently, someone on TV had asserted that by placing conkers outside the front and back door, you can reduce the number of spiders in your house by half.

Me - (Sceptical) "How?"
Mother - "You put the conkers outside the doors and it puts them off. They give off a gas which the spiders don't like."
Me - "So you're saying that spiders only come into the house through the doors?"
Mother - "How else would you get into a house?"
Me - "I'm not the size of a spider."
Mother - "They come in through the cat flap as well."
Me - "I don't think it's going to work."
Mother - "It is working. There are significantly less spiders because they don't like the conkers."
Me - "Maybe you just think that there are less."
Mother - "No, there are less. It's the gas."
Me - "Maybe the conkers are a secret signal known only to spiders not to go into the house. Like hobos with their signs."
Mother - "Maybe it's the spider sign for lady with a hoover."
Me - "Mummy, you shouldn't hoover them up. You should put them outside."
Mother - "But then they just come back in through the door when I'm not looking."
Me - "But I thought the conkers kept them out?"
Mother - "They do. It's the gas."
Me - "I'm not sure conkers give off a gas."
Mother - "They do. An anti spider gas."

I'm not convinced.