I have never seen the need for hot/boiling water in a SS tumbler.
I put the deprimed brass in my Lyman wet tumbler, fill nearly full with cold tap water, add 1/2 teaspoon citric acid, and give it a squirt of Dawn dish soap.
Tumble for 3 hrs. and the brass is brighter than new.
I rinse the tumbled bras a few times with clean tap water.
It gets dried on a dark towel in the sun in the summer and in the dehydrator in the winter.