Inorganics can have Syndromes, however it seems being eaten, splattered on the creature (coated), injected into the blood, inhaled is the only way to apply the syndrome (next to DF hack however I stay away from it for personal reasons) also if the syndrome is [ENTERS_BLOOD] and is coating a weapon and attacks with said weapon that can shear/cut a VASCULAR tissue will apply the syndrome. If the material is solid or said a "Sword" it get's magically held (Temperatures still transfers, don't hold magma) but since the sword just cuts it's not really contacting in the way the syndrome needs. I know if you search this board for "DOOM BOLTS" or something like that you will find special metals that melt when they are stuckin a target and apply their deadly syndromes.
I had an inorganic that was Sulfuric Acid (or did but it didn't stockpile right because it wasn't a creature extract, it was inorganic, so converted it) that it's wasn't hot, just liquid at room temp, and a contact syndrome of the local area of bleeding, pain, and necrosis (closest I could get) worked great.
But I've never did it with a Material_Template before which is why it took me so long to trouble shoot this (never had the issue before) and if you want I can either
a. fix up "1" creature of yours to a new complex way that works and looks nice so you have a template and understanding to follow or
b. I can find one of my complex creatures that I've done and share it's layout with you.
NOTE: These will be how I do it, and make it work nice. Doesn't mean it is the only and right way to do it, just my way for organization and application.