The method I have been using for over 2 years still works but takes time to set up. You gotta go in to your friends and put them into lists on facebook of around 99 people each. I found back 2 yrs ago that more than 99 in a list would hang up the system sometimes so I stuck to around 99 and sometime mixed it up doing some at 99 and some at 93,95,91 etc. So if you have 5k friends you need to create 51 lists. And then when you want to invite them, you will just go in and select invite list 1 hit submit, then go to list 2 and do the same from lists 1-51.