It may seem counter intuitive but maintaining your speed and keeping it constant will do more to keep you upright as your wheels are gyroscopes and when they slow down, they become unstable.

When you are riding through sections of slush and what we like to call the "brown sugar" keep your speed and your head up and don't focus on the patches of slush you are riding through but look a little farther ahead.

Reason for this is that if you are looking at what you are riding through your eyes will see the wheel moving laterally and you will over adjust while if you look ahead your body will adjust more easily to slight movements.

This should also help you relax which is a great skill to have when you are riding through sketchy sections... a death grip on the bars does not help at all.