I think most folks responding to this don't understand that the square grids are metal, and coroplast is a thin corrugated plastic sheeting.

So, if you put the coroplast on the inside, it would be smooth plastic that the snake touched, and it would be completed enclosed in insulating plastic. Heat and humidity shouldn't be an issue at all.

The problem isn't the sharpness of the edges, though, it's that the snake will push its face forcefully into any seams, and thus will scrape its face up due to the pressure, so you would have to seal the seams carefully.

I'm fairly sure zip ties will hold almost anything, but I'm not sure about the seams holding through the snake deforming the cage pushing on it.

The question about cleaning is very legitimate.