WF does not charge 0.3% for the sweep account unless you pick a special sweep account. It's in the fine print. If you pick the default or the default tax-exempt sweep account, there is no extra 0.3% fee.
Furthermore, no matter which broker you use, if you use a money market fund or money market account for the sweep account, then that fund has an expense ratio that gets paid.
Your sweep account is your PMA account (but not necessarily your PMA checking account which is something different). WF will move the funds automatically for you so you do not have to think about it.
Of course, the sweep account is paying such a paltry interest rate that you will probably not want to keep much money there. For example, I use VCSH for any and all the fixed income in my brokerage account.