You may want to think about a different way to secure the tubs without the duct tape. Tape inside of an enclosure is just asking for a vet trip. He can very easily get caught on the tape and get hurt by either removing it or him balling up around it. Not fun.
Yeah, I plan on checking the tape frequently to make sure it doesn't peel back off or something. That's why I wanted to do silicone, but o well. It's "guerrilla tape" which is beefed up duct tape, I'm hoping it won't let me down