I like use paper to write down my todo list, meeting notes etc and I use pencil to write. I later digitalize these notes.
Is there a machine or mechanism by which I can erase it in bulk? So that I could reuse the paper and avoid the guilt of wasting it.
The right solution to this problem is not to work harder and harder at erasing pencil from paper, but rather to change the materials you work with. I took a look at Rocketbook a few years ago, which IIRC you just wipe with a damp cloth, but ultimately decided to go with iPad and Apple Pencil. It looks like "Boogie Board" might be an alternative for short documents, and there seem to be more alternatives popping up now, so do some research. A search for "Rocketbook" will turn up a number of "best of ..." lists.
My solution is to write on paper that has already been used on one side, such as business letters I receive, or hard copy I make, that are no longer needed. I keep a pile of it, so I never need to write (by hand) on a fresh sheet of paper.
Then, the paper goes to a recycling facility (perhaps after shredding), so it isn't wasted even then, but has been given additional life before being converted back into more paper or cardboard. No new paper has been used.
If I need to continue writing when the paper is full, and I do not have any more with me, then I will turn the paper by 90° and write with a different colour ink, and on the original side as well.
You can get pens with erasable ink, this leaves the paper in a better condition to erasing graphite pencil markings, because the heat from the friction deactivates the ink, instead of scraping it off the surface, but it still requires the same physical effort.
Dry erase markers is a better alternative, but you will need a compatible surface. If you have a self-made / hand-drawn template that you want to reuse (or even if the paper starts off blank) a quick hack is to use a laminator to laminate the paper, then you can use the dry erase markers again and again.
In this case you could also look at purchasing a compact sized whiteboard to use in the same way. If you have a dry-erase surface that doesn't have any markings on it but you want to create a non-erasable template, then use a permanent marker for the template and dry erase or whiteboard marker for the notes that you want to erase.
Years ago there was a product which was used for removing pencil lead smudges on sheets of drawing paper. It was a porous cloth bag filled with finely-shredded latex eraser material. By rubbing the bag between your palms, the cloth bag would shed eraser "dust" onto your drawing. Then, by gently rubbing that dust over the surface of the drawing, it would scrub off the smudges. The more dust you applied and harder you pressed while rubbing, the more of your pencil sketch would come off the paper and it was possible in this way to erase a sheet into blankness with enough work.
This only worked with soft pencil lead and nonporous paper (which was called vellum).
If you have used the paper to make your list, then acted on the tasks, then the paper has completed its function. You are not wasting it when you send the paper to be recycled. It has done its duty and you have benefited.
