I used freeze dried petals to decorate our suite on the wedding night. While they worked for that instance I don't know that I would use them to throw or for an aisle. They smell very odd, plus you will need to travel with them, and you would probably also have to have someone in the wedding party set them up for you, I am not sure if Disney will do it. If you are having an escape I would just let Disney do it. You can also just have a basket of petals and every one grabs handfuls instead of paying for the cones etc. We had rose petal cones but I can't recall the price because we used Shelly from Impressions so we had to pay her separately for the cones and pay Disney for the petals. I think it was maybe $3 or so per person for petals.
I ordered approx. 66 cups for our suite and that only filled about two Publix/grocery bags (the plastic ones)! They weren't exactly cheap either, I was expecting a ton for the cost. By the time you pay for enough to cover the aisle, ship them or pack them, and everything else, it is worth it to just pay Disney the $200 or $300 that they charge to cover the aisle. I used flyboynaturals.com