How do I keep the nozzle/hot end clean while printing PETG?

[curious aardvark]

yeah well my advice is pretty much based on what works for me.
As well as taking the viscosity and flow rate of the material in mind.

pet-g, even at high temps, does not become the fast flowing liquid that pla does.
printing it cooler will tend to worse layer adhesion and a thicker flow that is more prone to stringing.

The really long retractions will increase blobbing. As you're esssentially removing it from the hot zone and then pushing it back in every time. That creates 'waves' in the material flow.
Likewise long slow retractions are going to make the flow uneven and create thick and thin print extrusion.

Shorter retractions are generally better if you can manage them.
The less semi molten plastic you're pushing and pulling the better.
And with most rigid filaments, the faster and shorter you can do a retraction - the cleaner the print will generally be.

I watch very few youtubers and much of what I do see, tends to be complete nonsense.

3d printing, is as much an art as a science. And what works for one person, won't necessarily work for someone else.

Also the pet-g you are using could well have a very different chemical composition to the stuff (creality white) that I've been using.

So anything anyone says to you, can only be a guide, at best.