Wedges, I've on the past couple projects used some half round wedges for some through tenons, On my latest project I have included rectangular tapered wedges, at a 1:8 ratio. 3" to 4" in 8 inches of length on the 2 inch thick wedge. After watching this video a few days ago and seeing the failed wedge get sucked in the the mortice in failure, I decided to give the traditional wedge a go. Specifically the white pine wedge in the photo at the end of the video.

https://www.youtube.com/watch?v=QgFXqcWn-hE