Can I DIY an anti-roost cone?

[Tofuchicken]

My eggs will hatch in less than a week and I'm going to buy a heating plate. I heard that the flat ones without the anti-roost cones often get pooped on by chicks. Is it possible for me to DIY an anti-roost cone? If so, what materials are safe to use?

 

[nuthatched]

Just cover the top with parchment paper or a towel you don't care about,that's what I did.