I have fought dirty (outside) nozzles since day one. Today I installed a teflon coated 0.4 brass nozzle:

"ENOMAKER Upgrade PTFE Coated Nozzle 0.4mm MK8 Non Stick Anti Stringing Extruder Tips for Creality Ender 3 Pro V2 CR-10/S4/S5 3D Printer Accessories Pack of 6"

https://www.amazon.com/dp/B0BJVJ11SZ?psc=1&ref=ppx_yo2ov_dt_b_product_details

(on Amazon currently for $10.99)

I've run 16 prints totalling about 8 hours print time since. The nozzle looks as pristine as when I screwed it in. Not sure yet about long term, but so far I like what I see. HTH

If anyone is having issues with petg with the stock parts, this build plate and nozzles have done wonders for me as far as adhesion and stringing. (Atleast once you get the z offset correct)

The stock plate would barely hold onto the petg for me, was hard to even get it calibrated.

https://www.amazon.com/gp/product/B087Q3CPQR/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

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https://www.amazon.com/dp/B0BJVJ11SZ?psc=1&ref=ppx_yo2ov_dt_b_product_details