I’ve tried the fabric sleeves and skins when trying to air pump, and due to them being porous, they won’t allow it to work. I’m guessing that the silicone sleeves will help both air and water pumping (especially if going for length, as mentioned by Stealth Man) far more than any fabric sleeve will. Silicone allows a seal to be created, while fabric doesn’t, so there’s the primary reason that the fabric sleeves won’t work for this. I suppose one could try to soak the sleeve in lube (to close all the pores,) and try it that way. I haven’t tried it, yet, but I might. I’ll let you guys know the results of the experiment, if I do.
My best guess is that, if air pumping, the lube will get sucked out of the sleeve, and cause the seal to fail. If tried with water, it will behave the same either way (wet or dry, as the water will wet the sleeve, whether you use lube or not, but I’m not sure if that will maintain a seal, or cause air to leak in.) Of course, this is assuming that the sleeve crosses the boundary between the pump’s ring. If not, it may work more or less as intended. Just remember not to overpump.
Happy Stealthing 🙂