We do not normally use Y-strainers for this very reason. If the stream is that dirty, it is not suitable for flush. If the particles are small, a cyclone separator can remove them continuously without plugging. We have used strainers with a blow-down valve on the bottom and asked the operators to blow it down each shift to prevent plugging. But, this is difficult to manage. And, it is only safe and practical if the stream is water.
Johnny Pellin