I've gotten about 15 to sprout using this, thought id share my design. The seeds will take longer than you thing to sprout a root, 1-3 months. I change the water ever month, and make sure the seeds stay at least half submerged, the very bottom has to stay wet.
Scale up 10 or 20 percent if the holes are slightly too small, but they work for most.
PEAL THE OUTER SKIN OFF THE AVOCADO SEED BEFORE PUTTING INTO THE WATER.
No need to let seeds dry out after opening the avocado, peel outside skin and let it soak for DAYS and DAYS, slow to germinate. (90 days)
PETG will last longer, with temp 235 and 60 on the bed.