I'm guessing it's not actually "weighted", he said he pushes his palm against it.
I do these so i dont have to deal with a towel, and you can do them laying down in any position. My fave time is nocturnal erections or morning wood. great way to utilize random hard-ons.
I could only hold them for like 1-2 seconds at a time when i first started doing them, now i can do solid 5 second resistance kegels