If he isn't going to do it, tell him to develop the well. He can purge it with air or a bailer etc. but it needs to be done with or without floc. He needs to get the well clean of any 'sediment' and then clear water.
You shouldn't have well screen, you'll have a rock bore well. Pump screen holes are too large for this 'stuff' to block.
BTW, shale doesn't do this but drilling mud and cuttings does.