Seems like I've answered my own question, however it's still neat to hear how anyone else is it doing this - neat and cheap solution Matt.
I found these little containers called dressing tubs by decor @ Kmart. They're little clear tubs meant for . . .dressing, the salad kind. Hole in the lid, thread wire through, solder strobe to the wire, clip lid on to container and a dab or silicone to seal the top (I drilled a hole just big enough for the wire, so nice and tight). They're $4.55 for a pack of 6 - a little bit more expensive than I would have expected, only need 25, so not too bad really. Not sure how they'll go in the sun . . . 1 month shouldn't be too bad.