I don't apply back pressure, I cease pushing down on the pedals and only use my legs to pull up, increasing the speed and causing me to pass all the coasting freewheelers... of course, if there's a light at the bottom I usually just do a series of skip stops to shave off speed, the skip stop mixed with slaloming is the most effective though. Applying back pressure down a hill is hell on knees, if you're that cautious about it just run a brake... or ted shred it