Wiffle balls?!? You mean this type of ball?
http://en.wikipedia.org/wiki/Wiffle_ball
I guess a score counter made with these would be the "Romper Room version" of the traditional score counter. "Need to slide a 'bead' over? Sure, hold on a sec, let me use both hands..."
Methinks ping-pong balls might be a better idea. That's what's used on the score counters at the Derby City Classic -- just some ping-pong balls on a taught wire, of which is stretched between two wooden posts. And you can get ping-pong balls in any color; you can do the DCC color motif of white balls, with every fifth ball being a red one (to indicate a milestone marker), or something along these lines.
However, if you're going to keep score in 14.1, ping-pong balls (and certainly wiffle balls) aren't going to suffice; you'll need to go the true bead route, starting off with 50 beads for each side (100 total), or maybe more depending on how strong you play / desired match length.
Hope this is helpful,
-Sean