I have one of those pet hairdryers that comes with a poor air filter design, like this:

https://www.amazon.com/Grooming-Adjustable-Temperature-Control-Nozzle/dp/B0B1MCQLX7/ref=sr_1_6?crid=5ZOHNBMM56LT&keywords=pet%2Bdryer&qid=1672117140&sprefix=pet%2Bdryer%2Caps%2C142&sr=8-6&ufe=app_do%3Aamzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bc&th=1

There are minimal holes, where most of the filter media is not even used. It ends up restricting flow and the filter clogs very quickly. I designed this modification that fix these problems, and it works superbly.

Print one bottom and one top. The top needs build plate supports, bottom doesn't need any.

To assemble, remove the original filter and cover. Trim the center of the original filter media pad for a tight fit on the center of the top part. Sandwich the media between the top and bottom, and screw on to the dryer with the original screw. The fit with the original screw is a bit tight; needle nose pliers work well if your fingers can't get it snug.

If you need a replacement filter, you can cut out a piece of Scotch Brite scouring pad or similar. Giving the filter media a very light coat of silicone oil will help dust stick to the fibers, making a very efficient airfilter (similar to K&N).