A few years ago I wanted a sleeve that had better scrubbing power because I was getting a lot of new customers and first cleans that were extra dirty. I opted for the porcupine (ettore) sleeve and was very happy with it for about 18 monthes, even though it lacked holding much water it just meant dipping it in the bucket a bit more often. I haven't been a fan of abrasive scrubbing ends on my applicator sleeves for a long time now, as they never lasted more than 25% of the life of the rest of the sleeve, so I started buying 10 packs of the wee sponge non abrasive scouring pads you can get in tesco and asda etc for 2 quid a packet. (sometime a quid in the pound shop) Since then I honestly would never be without one of these in my pouch pockets for removing occasional stubborn marks, or even stickers marks and anything else that you could think of. Once they are done (usually lasting a month) then throw them away and grab a new one from the packet. If you want to get them just make sure you choose the non scratch ones which are normally white in colour and NOT the green or black ones, as they will be too abrasive and scratch the glass. Even the white one's are obviously slightly abrasive to an extent or else they would be worthless, but still not abrasive enough to scratch the glass. Having these saves me quite often from having to use my windows scraper which to me is alway a good thing.