The safest approach is to avoid putting anti-fog treatments directly on the lens. Modern lenses usually have coatings, and applying household anti-fog products or soaps may leave residue or potentially affect the coating. If you want to experiment, do it on a cheap clear protective filter instead of the lens itself.

What helps most is reducing the temperature shock and keeping the glass slightly warmer than the damp air:

• Let the camera and lens acclimate gradually before shooting.
• If coming from air conditioning, leave gear in the bag or a garage/out-of-sun area so it warms slowly.
• Keep the front element very clean, since dirt can encourage condensation.
• Use a lens hood to reduce moisture settling on the glass.
• In very humid conditions, a lens heater/dew heater is the most effective solution for long exposures like star trails.

In places like Florida, some nights are humid enough that everything eventually gets wet, so acclimation alone may not fully solve it. For long night sessions, a dew heater around the lens or filter is generally the most reliable fix.