Definitely, wear the Sabre Skin without the Innerwear layered underneath. I have also folded it 2-3 time to make a fat donut shape and worn this to good club like effect behind the glans. Once past the entrance there is plenty of room inside the vagina just before touching the cervix. The girl did mention the next day that she felt sore from being worked over from the extended session!
No you would not need to go down a girth size on your Sabre Skin.