I would recommend against adding the coconut flake loose. I just finished a coconut beer, .5lb in mash and .5 lb in boil. I had planned on .5 lb in the secondary but found the aroma and taste to be spot on with what I was looking for so I skipped it.
Ok, so I found the loose flake to be a real bear to work with for a few reasons.
* It puts out a lot of oil which made my siphon very ineffective
* A lot of my coconut suspended and didn't drop to the bottom (This kind of flabbergasted me)
* Obviously could not wash the yeast afterwards (If this matters to you)
* Cleanup was neigh impossible with the mess that this **** causes
My next batch will involve boiling my coconut in 1g of water for 60 min to extract as much flavor as I can. I will then refrigerate the liquid to solidify the fats left by the coconut and then strain it out - leaving the coconut flavored water. I will be using this water in the mash or secondary.
Feel free to do what you want. I just wanted to share my mistakes to hopefully help lead you down a path more in line with success