Bleach should be less of an issue, maybe not a non-issue, but substantially less of one.
At least with bleach you should be rinsing very thoroughly, and be eliminating all but a very small trace of the surfactant and thickening agents.
On a fishless cycle, the ammonia is going into the tank, and you'll do a 90-95% water change at the end, but that means 5-10% of the total amount added stays behind in the tank. That's a lot more than just a thin film....
Note: The surfactants used in both products are *probably* ones that aren't going to be very toxic to fish.. but strangely they never label which exact surfactants they used, making it hard to know for sure.
Last edited by mattinmd; 10-31-2014 at 07:57 PM.
Reason: spacing, double % sign