u/Glad-Marionberry-382

So just moved into a new place and one sink had clearly visible paint poured, and dried in the drain. Draino took care of that! This other sink had this mystery substance that looked like clumpy soil when dry, hair when wet but seems pretty tough..
Second thoughts it seems similar to the appearance of straw or sisal (the cat scratching materials).

Ive fixed the obstruction, I’m just wanting to know what anyone thinks it could be.