I am sort of amazed at how many people clean their stylus with every play. I hardly ever need to clean the stylus. I keep my records clean and that seems to be good enough so that I only bother to clean the stylus once every ten or so sides.I used to think the same, until Jcarr explained why more frequent cleaning is beneficial.
Even if one's LP grooves are perfectly clean, the stylus collects molecular-sized bits of vinyl as it plays. These get burnished onto the stylus surface by heat and pressure at the contact points.
Cleaning every ten sides or so allows this layer to accumulate. The degradation in sound is gradual and subtle, but it occurs (slighly muffled HFs, loss of lowest level detail, diminution of micro-dynamic "snap"). The color of the stylus will also go slightly yellow, compared to the pure white it would be if perfectly clean.
ME after each side prevents this buildup. I've seen and heard the difference on styli that are cleaned less often. Thus my recommendation for more frequent cleaning, based on guidance from one of the world's best and most helpful cartridge designers.