I didn't go with the sulphuric acid route. Do to safety concerns. As well as I didn't have any of it left. So I just put in 2ml of nitric acid with heat. As it warmed I eventually added 2-3 more ml of nitric. Kept warm. Then I tested with stannous and this is the result. After a few minutes. I'm not sure if it's clear enough but there was some darkening. As well as some reddish coloring but that since went away. What y'all think? Yes there is pms'? The other picture is of the waste material in a 1000ml beaker.