been looking at wet n dry vacs as pressure washers use them to suck up the sludge but im wondering if its worth the hassle, the one i saw had a drain tube at the bottom so you can drain the water out but doesnt the water stay at the top when you collect blockpaving sludge ina bucket? it seems too. and then the weight of the vac when its full would be heavy to lift in van? and its more stuff to carry. is this a neccesssity or just a gimmick? the old bucket and shovel i have been using for years.