Icy's proc rate is incredibly bad and blizz
knows this, they may eventually fix
it
You only put icy on a mainhand(nothing under 2.8, unless its a shadowfang), ofhand will show little to no results as you've seen. And rogue is probably the only class that can get it to proc reliably, maybe warr but they already have a slow.
If by reliably you mean once a match then yes, I tried icy on a CB and it would proc maybe once a game at best. I would gladly exchange fiery for a working icy but that enchant has been broken since vanilla, blizz even aknowladged it's proc rate is prohibitive of use but doesn't seem to be in a hurry to fix it.
You'd want icy on as slow a MH as you could get and have a thrash blade OH so that the MH procs from thrash have highest chance of proccing icy, aswell as SS having a higher chance of proccing icy.
Hit Rating - If I'm having a rant at you about hit rating, then read this.
Icy is a horrible enchant with a horrible procc rate and should never be used by anyone for any reason at all, except maybe for some show-off lolset.