forcing a reload of the cookies

Question

I have an web app that is based on razor where I am setting a few cookies when they first load the screen based on a guid passed in.

So, the url would look something like:

https://url/CustPortal/Account/Logon/DDE4BBFB-0D2E-4706-A604-36EEA3FDCAE3

Once I validate the guid, I am setting the cookies such as the css from the database.

This part works fine. The problem I'm having is if the guid passed in is different the next time they visit.

The cookies are being set, but it's not using the right css. I can CTRL+F5 and that fixes it but I cannot rely on the customer to know this.

Is there a way to force it to refresh on each visit to the site and not use the cache?

Hope this makes sense!

Thanks!