Ah sorry to hear that! I took a ball of paper and shoved it through a few times to get rid of any strings, then sprayed some dry PTFE to the inside. I have one made in PETG HF and one in ABS GF and they haven’t clogged for me yet… But most of my multi-colour stuff is PLA so the difference in melting temp vs ABS and considering PLA doesn’t stick great to PETG helps a lot for me.
I did model a larger diameter one and print it but didn’t upload it because the regular one wasn’t clogging for me.
I think if it’s a material sticking issue, a larger diameter probably won’t be much more reliable - maybe it will store a bit more poop so you have more time to shake it out but - it’s prob the PETG/PET combo that makes it clog.
I guess oil/grease doesn’t last forever, I wonder if there’s another treatment that could be applied. Like enamel spray paint or something…