Easily make a power tool pipe cleaning brush with old/dull hole saw.

Or you can buy the following: The blue monster cleaner which broke after using it for little while so I listed links to other recommended brands below too. Monster pipe cleaner: amzn.to/3Hj5LDV
Link to other recommend brands:
amzn.to/3S0V7Xl
amzn.to/3vuzWFC
DISCLAIMER: This video contains affiliate links, which means that if you click on one of the product links, I'll receive a small commission.

[@richardmccann4815]

You can buy one that does both sides for 15 bucks. Better you should braze new teeth in the hole saw!