Rinse under distilled water and use a plastic comb or brush with stiff bristles for some light scrubbing. Set it aside to dry. That's pretty much it. The felt pads will last a long time.
To add, and to concur with what Pioneervato said, that yes, during a cleaning run, with these type of machines that use a Vacuum Wand (VPI, Clearaudio, etc) it is good practice to inspect the Vacuum wand, as you go. One might note a buildup of fuzz on one of the Velvet Strips.
And as he says, a simple matter of just quickly rinsing with some distiled water, and a soft clean toothbrush. Shake excess water off, and you're ready to go again. Then after one is done with a cleaning run, again clean in the same fashion, pat dry with a paper towel, and set aside to fully dry.
The reason you'll note slightly more accumilation of dust-dirt only only one velvet strip, is because the Vacuum Wands themselves are supposed to have theie vacuum slot angled slightly off a degree, or two from being perfectly perpendicular to the record, to enhance fluid removal, and as well probably, less chance of record damage.
The original Velvet Strips are good from anywhere to 300-, to maybe as high as 450 LPs, dependent on how well you care for the wand, and just how dirty the records are that the vacuum wand will encounter over time.
One can then either buy an entirely new Vacuum Wand replacement from VOI, or Dealers for about $26-$30, or one could also buy replacement velvet strips from somebody like the Disc Doctor. Cost I believe is $15 for 4 replacement Strips. One can then just peel off the old strips, degrease the wand with a solvent such as Alcohol, and re-apply.
Since the Disc Doctor Strips are slightly longer, and wider than the originals, some cutting to length might be needed to duplicate the originals. Mark