That's just what I've read in the forum here through the years. Most of the advice I came across said don't boil/heat the water, for a better quality CS to go slow. There are folks who will use the hot water, but I prefer not to. Really, the amount of time it takes the Silver Puppy to make a batch isn't too horribly long, and I'm patient.
FYI: I use mine on Swap mode, on Auto, with a mag stirrer. Room temperature distilled water. I use a quart jar, and it always comes out clear or sometimes maybe a really, really, light yellow. Only time I've gotten more yellow is if I accidentally turned off the Auto, or if someone in the family shut it off and I turned it back on so it was "brewing" longer than planned. I don't use the silver rods that came with it but some .9999 I bought elsewhere, because I wanted to use purer silver rods than the default that shipped with the unit.
If I was wanting to go a little faster, since I personally do not want to go the hot water route, I would just "seed" the distilled water with a little CS from my previous batch ... that would let it start with some silver particles there at the start so that the electric current will be there sooner. Just my personal preference.