Would the laundry setting a minimum & maximum threshold in full amounts fulfill your criteria?

(e.x. minimum amount is 5 BTC at a time, maximum is 20, the only possible other amounts are 10/15)

Obviously transactions that could be pinpointed (such as a 6.8775 BTC) are not fit for laundering,
so using laundry-predefined full amounts would definitely obfuscate the origin & identity of the receiver if there is large enough volume on the site.