First, let me say I have read many other posts on this topic...

my issue is that after making and wrapping it, when I go to use it, it seems oily and non cohesive. 

After reading some posts i see some let it set out on a sheet pan before wrapping it.  I was taught to wrap it straight away and let set overnight.

What’s m worked best for you? I was hoping to use MC instead of fondant.

thanks

I use modelling chocolate to cover my cakes instead of fondant, simply because it tastes so much better.  There's a simple trick to it:

After mixing the corn syrup and melted chocolate, turn it out on the counter on top of waxed paper.  AS SOON as it's cool enough to handle, knead the excess oil out of it.  It will be crumbly and oily, but keep going  -  it will smooth out and be beautiful.  At this point, treat it just like fondant. Cover it with shortening and double- wrap it and DON'T refrigerate it. Let it set several hours (or preferably overnight) before using.  You might need to warm it in the microwave for a few seconds when you begin.

Modelling chocolate tends to be softer than fondant so if I need it to hold its shape, I'll add regular fondant to it.  I've added up to 50% fondant without changing the taste a great deal.

One last thing - - most recipes I've seen call for too much corn syrup.  I generally use 24 ounces of chocolate and 1/2 cup of corn syrup.

Good luck.