Please read about the difference in wet and dry use of your Philips electric foot file.
Can I use my Philips electric foot file wet?
Using your Philips electric foot file wet and dry.
Yes you can use Philips electric foot file wet. But wet use of your electric foot file is not as effective and smooth as using it dry. Also, wet use changes the sensitivity of your skin and gives you less indication of how much callus you have already removed.