I was surprised by the material when I got this. I thought it was going to be a rigid container, but it's a nice soft container (which now makes sense since you need to squeeze it to make it work). It seems extremely durable and is light weight. I almost wish now I got the larger one, but I'm thinking the smaller one will be better for travel and carrying along, etc.I didn't get to actually try it with dirty water though, so I can't speak to the functionality.