That's already pretty cool! It surely does generate very random numbers. I still think you can take it a step – or a random number of steps, hah! – further by repeating the process a random number of times! Maybe this way we can reach maximum randomness. Probably need to reroll the number until it's big enough for that.
I would also check if the result is 4. If it's 4, it should be discarded. 4 is not an actual random number but a joke random number from a comic.
That was an unexpected dark turn. Glad you live to tell their story!