Much like how socks disappear from dryers I’m finding rogue filament (not stringing) dropped into the print job. I have to keep clearing it off. But I don’t know where its coming from. Anyone know???
It may be filament stuck to the nozzle that haan’t been cleared by the cleaning roller. Sometimes it doesn’t get it all. I have found adding a single skirt loop (others tab - skirt loops - 1, skirt height -1) prior to the print starting tends to take care of any left over.
What infill pattern are you using? Grid infill tends to generate “bits” of plastic that eject from the model.
Poop sticking to the nozzle happens more often with PETG than PLA. A cleaning tower helps a little but needs much more waste material than simple skirt.
So use 2 skirts. Or pause and manually clean the nozzle with a brush prior to the print starting? 
I’m always a little surprised at how many people have have trouble with PETG.
I really liked your skirt recommendation. 
I always use a skirt on single color prints as well. Even with PLA as it is an ingrained habbit 
Since I am currently mainly doing multicolor I usually have a purge tower (looking a lot like RocketSled’s 
). That takes care of all of the dragged PETG poop on higher layers after a filament change.
I got many typical PETG issues covered for my prints, but am still struggling with the overhang performance. Lots of other, very good threads here for that But it just seems to be particularly difficult, especially with the high flow filaments.