The poll will be skewed in any event. The 'safe' answer is "it doesn't work and I never thought it did". That's an easy choice to make. Further, there is bound to be a certain amount of ridicule for those who believe that it does work. There will be even more ridicule for those who claim to have had success using such a technique. Those folks will probably refrain from voting.
And yet the utility company still allows, even encourages, the use of dowsing and, presumably, they find it worthwhile. After all, they're in the business and time is money.
The results are what they are but the poll is not statistically valid. People lie to pollsters. Remember the last election? The polls had voters saying one thing but voting another. Or the poll only measured 'blue' areas. It is not valid to simply sample New York and California - at this moment in time, they are political outliers.