Biting the old style batteries that are old carbon zinc primary batteries would work to help make them last longer.
The old carbon zinc primary batteries were softer and could easily be bitten and dented by biting them.
By biting the old carbon zinc primary batteries it brought fresh material in contact with the electrodes which gave the old batteries a temporary boost and charge so they lasted a bit longer.
The new style batteries that are made with a harder steel jacket such as the steel jacketed alkaline batteries would be too hard to bite down enough to make them last longer.
You could however use a pair of pliers to squeeze the batteries and squish them to make them last longer.
But then the batteries may decide to leak out acid etc and may not fit the device anymore.
The batteries will last a bit longer when you squish the batteries but they won't last much longer so it's not really worth it.
But you can try it if you want too.