Rock hard icing sugar, bin or bash?

[InWithTheOutlaws]

I have two bags of icing sugar that are hard as rock. Are there any magical MN tips that don't involve fuckloads of effort bashing it - I did try this before and I got slightly smaller but still ridiculously hard lumps....this look like hours of effort! Surely there is a better way? Or even a reliable brand I can try and get a hold of real quick? (DCs birthday parties fast approaching and tension mounting!)

Blender? Esp. If it has a grinder attachment.

I have a teeny tiny blender (for spices really) - it's not going to make much of a dent 😔.

Yeah, I just used a coffee bean / nut / spice grinder and it largely did it. I only blitzed it a few seconds though, I should've done it longer. My question is though, is it still safe to eat? I know honey and sugar doesn't technically go off and I used this same icing sugar (for chocolate shortbread which I'm using it for again now) 2 or 3 weeks ago and it was ok but seems a little harder now. Even though I blitzed it, I had to take 3 or 4 little lumps out (about the size of little fingernail) cause I still couldn't crush them with my hands as it was absolutely rock solid.