Not usually. People normally strain their lye when they use an opaque liquid (such as milk or coffee) to dissolve their lye in. They can't see whether there are any undissolved lye crystals remaining, so they strain it to be safe. They could also be using a liquid with fat in it, so they are straining out bits of saponified oils, which sort of makes no sense if you ask me.Is this why people strain their lye? I've never seen and could never work out why people strain the lye in videos.