My mate did this. I actually whitied it was that strong.
Get a spoon of butter and heat it up, drop in say half a gram of Iso (by Iso I'm presuming that we're talking about Iceolator hash yes?) and let it mix in with the butter. Then stick the spoon into a yogurt and eat up... I've never had a stronger effect from any cannabis than this.
I ate a 1/4 gram of nl5xhaze iceolator in this butter in yogurt method and wound up mind racing stoned out of my head. Spewed up even lol. I had smoked a lot of weed too but as an experienced smoker I would say my dose was too high.
You could apply this method to putting the butter into other things than yogurt also. It apparently works best with something fatty though so maybe ice cream or poured into a cake.