PET is used in plastic water bottles, PETG is considered a contaminant and typically not part of the recycled waste stream, at least in the US. Same for PLA.
Although as you noted to pelletize plastic a blender would be a good place to start. The question then becomes what do you do with the pellets of plastic?
From my understanding it takes a system like this
https://www.filabot.com/products to produce filament from waste plastic. That’s not to say you can’t used the pellets in some other way.
I am not opposed, assuming there isn’t a severe quality concern. I would rather like a way to recycle my waste plastic. There isn’t really anyone local that will recycle PETG or PLA.
I am still developing technique but it’s relatively straightforward.
Spray pain on water, then dip the piece. It takes a little practice to start getting some good results. Rotating slowly as you lower it seems to help. Dipping more than once can be a smart idea. Warm water is better than cold water.
I am in California so PST