If you're gonna do it, it should be "scud walking""   

Fair enough, just like playing with fireworks as a kid there is a smart way to do a dumb thing and a dumb way to do a dumb thing.  The pilots who maintain a speed that out flies their visibility combined with operating in an area that they are not absolutely familar with the terrain/obstacles is a recipe for diaster, see the 407 down south that hit the power lines a month or 2 on the job, in the fog at over 100kts.

All of us here if asked to repo a helicopter from one side of the airport to the other with 50' vis and 50' ceilings could do it.  We would literally be walking the thing down the taxiway but all of us could control the aircraft with the slightest references out the window or even the chin bubble.  For us here working part 135 our GOM and FAR has on ground long before it gets that bad provided you follow the rules.  If you are 91, especially back before they changed the class G visibility rules, you could find yourself in a completely different set of circumstances and it was up to you not to do dumb things the dumb way.  Slower and lower as required and never giving up visual references and knowing with 100% certainty of what was ahead and operating at a speed where if the 1/2 mile vis you are working with suddenly turns into a wall of fog the ability to easily come to a stop/turn around or land without any significant manuevering.  

Enroute decision points and good judgement should have you turning around, diverting or landing long before you get forced into an uncomfortable relationship with the ground.  But if you do continue to press forward, slower and lower that would ultimately end with you in a hover, looking at the top of a tree through the chin bubble.  Then slowly walking from tree top to tree top till you find an opening to land in.

If there is an precip then know at what speed the wind isnt going to clear the water off the windshield, in the AS350 series its around 40-50 kts.  If you need to go slower than that to maintain adequate reaction time with precip you need to stop what you are doing or things are not going to end well.