How many times have you gone to the paint locker and found a coffee can full of ruined brushes soaking up the their handles in paint thinner?
If you must soak a brush for a little while, there is a way to do it so it doesn't become a sticky mess. Just wipe off the excess paint from the bristles and set the brush in a can with about 1/2 inch of solvent in the bottom. Wet the bristles and dissolve some of the paint. Use no more than a little thinner for this or the thinner will soak up into the ferrule and swell the bristles up.
A brush can sit for quite a few hours in this small amount of thinner because the bristles wick the thinner up and stay wet. This method will keep your paint locker cleaner with no big spills to clean up.