This is the trouble with VP's. Without being able to culture a virus in a lab and see how it behaves in vitro how can you say whether it is contagious or not.
Anecdotally people who swim (kids in particualar) do seem to get more. This is not, however, necessarily evidence of contagion! Could be that micro abrasions in the skin from non slip surfaces make the feet more vunerable to lesions from naturally occuring skin flora and fauna. Could be demographic. We just don't know.
Be great to find a kid with vps, get them to tap dance on a wet non slip surface than march a random 200 other kids over the area and see what happens. Ethics commitees can be so petty sometimes!
I say cover em up and hope for the best. Compeed works quite well if you can't get the patient to agree to duct tape of the pool to agree to band aids!
Good luck with that. The curse of "everyone knows" is a hard thing to fight!
Regards
Robert