If you are serious about a hack, it will be better if you could replace two front wheels with this type of wheels.

[![enter image description here][1]][2]

For this you could reach out to a repairer. This would help you to avoid inserting pencil eraser frequenlty. I hope you know about the working of these stoppers and would be easy to get started using this stoppers. I am not branding this same product, you could go for similar types.

  [1]: https://i.sstatic.net/qtpTgm.jpg
  [2]: https://i.sstatic.net/qtpTg.jpg