I made a tool out of a C-Clip tool.The typ when U squeze the handle the pliers spead out. ground it down so's when u stick it in there an sqweeeze it presses to holes through the shank of the grommet into the wood.it's a pretty weird shape on the tool like a big A with a little T on top.No pics I'm a computer moron.
Take a hardwood dowel, same diameter as your plug. Drill grommet hole in it, just a hair bigger than the grommet (so you can get it back out easily). Take a scrap piece of wood and cut a half circle in it that is the same diameter as your plug. Insert the grommet into the dowel, place the half circle over the grommet and smack with a hammer. Your grommet now is bent with the same shape as your plug.
Tagger,i can't picture your method in my head When you get a chance could you post some pics? For some reason i can pound the 7mm in with the mallet and shape them to the plug,but not the larger grommets Thanks