Andi, I'm sorry I can't tell if you were kidding or not about sending people multiflora rose. Just in case you weren't joking, here's some reading you might look at before you send out any multiflora rose:
http://www.eddmaps.org/Wildlif...
There's several links on that page describing how invasive and destructive this rose is, and maps showing how many states have it on their invasive (banned) lists.
Anyone finding this rose on their property should take steps to get rid of it, and should stay vigilant about watching for it to regrow.
There's been quite a bit written about the history behind multiflora rose and Rose Rosette Disease, so I won't go into all of it, but I will say your best way to prevent losing your roses to RRD is to remove any and all multiflora roses.
Yes it is used as a rootstock, but that is a whole different cup of tea. No issues with the rootstock.
Again, sorry if you were joking, I tend to take things literally.