Potluck allows you to do this very thing. The goal and what i'm working on currently is to have a network of user owned machines to power large models for each other. This is on your own machines, or machines that you have in an office space, or eventually machines all linked together via Potluck. Each idle gaming computer or laptop lending compute power to other people who are running Potluck and vice versa.
Try it out, and me know if you have any questions or comments and i'll do my best to answer!