How do you form Marshmallow Ropes? I have made marshmallows before and formed them into a pan, and then cut them into squares. That works fine and they taste great.  

I'd like to achieve the effect of the long marshmallow ropes that I have seen in France.
I tried using a piping bag with a big tip and piping them onto a sheet dusted liberally with powdered sugar, but mostly they just stayed stuck in the bag and made a huge mess with limited success. 

I'm looking for suggestions on how to get this effect.

Is it possible that the recipes that use more egg and less gelatin would work better?
Have you tried using a marshmallow recipe that is only made from gelatin and cooked sugar syrup (sugar, water, and light corn syrup to soft ball stage, 240 degrees F)?

I have made various piped marshmallows that will hold swirly shapes using this type of marshmallow recipe.  It is a bit more stable than the egg based recipes. The most important thing is to make sure that the marshmallow mixture is whipped to a nice fluffy, shiny, smooth stage (about 7-10 minutes on high speed) and piped very quickly into whatever form you want before it sets up using a large round tip.  Timing is of utmost importance here and you may lose some marshmallow during this process at home.

I would also recommend piping onto a silpat (silicone) lined sheet tray or a piece of wax paper that has been lightly dusted with a mixture of cornstarch and confectioner's sugar.