I wash mine at the end of each season. I've had my original wicks for several years. They only started to fray after about 3 years.

The "water proofing" effect also limits the amount of fuel they can absorb, in my experience. The soot builds up and acts as a barrier.

However, that is the only reason I do it. It doesn't stop anything from turning black. It doesn't take all of the soot off.

I've also accidentally left mine in the rain, in a bucket and had them soaked.
They dried out just fine without issue.

The whole "ruined by water" thing (as long as you aren't stopping bullets ) completely mythological.
_________________________
Pele
Higher, higher burning fire...making music like a choir
"Oooh look! A pub!" -exclaimed after recovering from a stupid fall
"And for the decadence of art, nothing beats a roaring fire." -TMK