I imagine linen would be helpful but I've never used it. I've got a latigo strop from Tony Miller, just leather, and it does me fine.
I think the idea is that it's a mild abrasive so it helps kepp the edge a little longer.
I will pick one up one day but I'm in no rush.
If you're learning to hone I think a bit of balsa with some chromium oxide on it might be a better, and cheaper, option. It seems to iron out issues in my poor honing technique. I can come off a thuringian or Chinese 12k then go to leather and it often feels rough, the cro ox makes everything smoooooth. I had planned on avoiding pastes to get my honing down but the easy get out is always tempting.
Sometimes I use the rough leather side of my strop and I've heard people, Arrowhead, getting decent results using newspaper. The ink is a mild abrasive.
When learning I rekon coticule>cro ox>leather might give a better result than coticule>linen>leather. I've never used a coti though.