Form field caching

We will be using our checkout form on a shared computer and would like to not have the form fields cache between users. I already have autocomplete turned off in the browser and am using autocomplete=”off” in the form tag. I couldn’t disable cookies completely since they are needed to get from the products page to the checkout page. None of what I’ve done so far is working. Any other ideas? Maybe a function out there where I can reset the fields manually after a successful checkout?

https://ww.wp.xz.cn/plugins/wp-e-commerce/