Let me share a few insights about a wash (or clearing) account and guide you in getting started.
First off, I've found a related interaction where @Rustler said, "A clearing account is just an expense or asset account you use to move value into and out of. It is not a type of account, rather clearing is the name." So, I recommend asking your accountant how to specifically categorize each transaction associated with your wash account.
Secondly, if you haven't already, there's a great chance that your accountant may ask you to create a clearing account in your Chart of Accounts.
Here's how to create a clearing account:
Go to Accounting, then Chart of Accounts.
Under Account Type, select Bank.
Choose the appropriate bank account on the Detail Type.