I also brought this up many times, unfortunately it is not possible using pure mimble wimble. The closest thing would be to use something like Mingle Jingle:
Unfortunately that would require a consensus change and is also not without its disadvantages.
Therefore I would argue the safest solution is to just auto empty the wallet at fixed times, e.g. weekly or after receiving a fixed number of transactions, e.g. 60. This fits with theRFC for HD wallets and one time use addresses which should make this more easy and standardized: