I decided that avocado seeds were not edible based on the result of simple boiling experiment. The seeds are as bitter as raw avocado pulp. The pulp bitterness diminishes as the peel chlorophyll degrades and the pulp itself gets softer. The seeds failed to follow the scheme however.
Someone suggested that boiling it several times might do the trick. The bitter substances will be dissolved in water. The bitterness might go out completely after several water changes.
There will be no harm if I do a second trial. After making avocado ice candy, I saved some seeds for the experiment. I scraped off the testa and sliced it thinly. Diffusion of substances from seeds to water is efficient if the slices are thin. Boiled it in three generous amount of water batches, five minutes each. Fourth boiling was not done cause the commodity was too soft after third boiling.
Time for evaluation. I got a slice and took a small bite. It was not bitter. I took a second and third bite. Then the bitterness slowly came to my senses. It was still as bitter as the raw seeds. It was perceptible after gurgling water and even after eating lunch. About one hour bitterness.