Volumetric Dosing Medium

I am planning on dosing out 4-aco-dmt volumetrically. I originally planned to use sugar cubes with 150 microlitres of water containing 15mg of 4-aco-dmt but I now worry that this may be enough water to significantly break down the structural integrity of the sugar cube. I am also considering marshmallows since they are rather porous. Any of you have other tips or ideas?