This article describes how to set up a cookie blocker extension on Google Chrome to prevent cookies from the sales representatives from getting synced to the customer's contact record.
Download the cookie blocker extension from the chrome web store
Navigate to a new tab in Google Chrome and click on the cookie icon in the menu bar
Click on the settings tab on the far top right, as shown in red in the picture below.
Click on "Blocked cookies" on the left menu bar and click on the "Block cookie" button on the right.
Set name to "hubspotutk" and allow domain and value to be any.