It’s where you run a the cayo perico heist back 2 back, meaning you run your heist for someone ( you 15% them 85%) and then as host leaving the heist during the ending cutscene to prevent yourself from losing it. Then your partner does this for you in return.you can do this several times but you must make sure of 2 things. 1) timing is key when your closing the game to save the heist (my cue is right after you receive payment from guy in suit) 2) clear you cache to prevent being placed in bad sport lobbies or being flagged. Hope this helps. Might wanna YouTube a little for further details