I too want to know, as I am on a zebra-mussel infested lake. I will be changing out my non-cleanable clamshell raw-water intake for one that can be more easily cleaned of the offending critters. Probably just a simple mushroom thru-hull on a flanged seacock.
I will need the second line of defense that a strainer will provide. Definitely interested in learning more about and getting recommendations for a good strainer.