I must admit I rarely prevac so this could contribute to the clogging. John, the CFR is not sold on the fact you use less water and so is more eco friendly, to be honest noone cares about water usage, it is the fact that you have to refill far less often and so can use a good 400-500 psi non stop for a few hours. I've only ever used a CFR but I hear that it is quite a big issue having to dump and refill on a conventional machine. It's only the basket filter that usually needs cleaning whilst on the job but you simply pull the inlet hose top off, scoop out the debris, and put the top back on, whilst the machines still running.
The wonder wand is a great tool also, when used with a cfr you can hold it over a stain and continuously flush it without over wetting. Again, I haven't used a conventional wand but if the wonder wand can do for cleaning what the wonder bra has done for women, then its a good tool.