This is a good idea, but I might use more durable paper towel rolls cut in half instead. All the world’s toilet paper is soaked in a special form of PFAS/forever chemicals that make paper much more soluble in water, or less likely to stick to equipment during manufacturing. That chemical can bioaccumulate in plants and soil, contaminating it for decades, unfortunately.

theguardian.com/…/toxic-forever-chemicals-pfas-to…

Toxic ‘forever chemicals’ found in toilet paper around the world

Research finds waste flushed down toilets and sent to sewage plants probably responsible for significant source of water pollution

The Guardian
the pots are made from the recycled cardboard part in the middle. pfas in tp are used to make the paper more easily flushable, so i doubt it’s used in the part that wasn’t meant to be flushed anyway. tp however wouldn’t be a good material, because it’s not sturdy enough and almost everytime bleached. however i saw that tp in some countries doesn’t have the sturdy cardboard part in the middle and now i realise that you probably talk about the cardboard in paper towels because we are talking about the same material…
Oh yup, I meant the brown middle part in paper towel rolls!