Once the creator or a subsequent owner of a work applies CC0 to a work, the work is no longer his or hers in any meaningful sense under copyright law. Anyone can then use the work in any way and for any purpose, including commercial purposes, subject to other laws and the rights others may have in the work or how the work is used. Think of CC0 as the “no rights reserved” option. CC0 is a useful tool for clarifying that you do not claim copyright in a work anywhere in the world. In other words: You can use the textures for any purpose, including commercial work. You do not need to give credit or attribution when using them (although it is appreciated). You can redistribute them, share them around, include them when sharing your own work, or in a product you sell. The only thing you can’t do is claim to be the original author of the textures.